Well I've run into a speed bump in rebuilding my Bianchi Giro. I've managed to separate the steel bearing surface from the aluminum lower cup of the Athena headset.

I have a home made headset press using the Park bushings. Installation of the cups seemed to go fine, but the lower bushing was stuck in the cup when all said and done. Still not sure how that went down as it seems to seat nicely. Anyway I removed it by taping up the spread flanges on my cup removal tool (to the one inch diameter) and tapping out the bushing. Unfortunately the steel part cup came out with the bushing! I was able to get this off the bushing by using a set of wide pliers and banging the bushing on the floor. Fortunately all this was done with any apparent dings, deformation or damage so far. I was going to take a picture at this stage but while experimenting with the parts I test fit the steel part and it stuck into the cup so I went ahead and used the headset press to get it back flush with the lip of cup. There is still about a 2 mm gap on the inner side though so I need to figure out a way to press it back in all the way, so this is where you folks step in.

My options I'm considering:

1: A golf ball seems to fit in pretty nicely. Hammer on it with a golf ball

2: Build up the headset with loose balls, install the fork with those and tighten the bejesus out of it.

Other thoughts?

Not sure I followed all that, but I would use a piece of threaded rod and stacked washers big enough to bear against the outer rim of both top and bottom cups. Thread nuts onto the rod and tighten until it is seated properly.

That is how I always do it. I don't own a proper HS press.

I agree, all thread comes in very handy and you can add a slide hammer at the top to add upward pressure. Add washers, put it through a socket or whatever.

I am not quite clear either, but it sounds like the steel potion needs to go further in? If that is the case I found certain socket makes, in the size of about 13/16's seem to fit the head nice and tight. You could use one to tap the steel further in.

Like to see a pic of your headset press. It applies pressure on the races, not the cup edges?

Maybe just build up the headset with proper bearings, press cups flush and install and tighten fork. I'd be hesitant to apply pressure to races with anything else, (although golf ball sounds like a decent McGyvor)

were these steel races GLUED into the alloy cups in Athena HS? I know Campy used some sort of semi-rigid elastomer (SELFORM?) in some of the early 90's HS (such as Chorus) but not sure about the entire line or how long that practice was applied.

Edit: I can answer my own question: Athena did not get the SELFORM addition, only Croce d'Aune,C Record and Chorus were so blessed.
However, if there's a any looseness when you get this steel race pressed back (as a result from forcing it out accidently) you might get yourself some Loctite GREEN with "wicking" properties, then it would be glued in.

Heat will expand the aluminum cup far more than the steel race, allowing the race to fall into place with minimal force.

The cup should be hot enough to boil water, not much hotter than to smoke oil.

You were quite lucky! You are only supposed to use the flat end of the bushings (or no bushings with the Park press) to press in this vintage of Campag headset!

I've seen the inner race cracked by using the smaller end of the Park bushings, even happened to me, ONCE!

OP - your option 2 is a no no.

I like dddd approach only I might put a pan on the stove with water and heat everyting up with the race side up. It might just fall into place. If not, with a little persuasion, it might go in a lot easier. Next step would be a torch to heat, but I don't like the idea of non-uniform heat application. Maybe if you have a small enough burner or camp stove burner or sterno can .....

Thanks all for the replies, some good food for thought. I've attached a drawing to help clarify. Apologies for my drawing to the artists and engineers out there. The Park bushings rest on the inner shoulder of the cups, not on the race. This was second time I've used them, first time was for a modern new 1" Record headset. This Athena headset is from a 1989 bike. I can't appreciate any type of residue that looks like glue. I got the bushings to help keep the cups straight while pressing in, and they do a nice job of that. I'm going to mull over options. I'm hesitant to use the actual bearings because I think the pressure might deform the cage.

I thought your description was pretty good. The picture validates what I was visualizing.

I worked at a place that was challenged with bearings needing to be places several feet from the end of a shaft. They put both in a deep freeze overnight and just slid them on in the morning. Thermal environment change could do the trick for you. Freeze the race and heat the cup.

i have been known to throw a cup on the BBQ for a few minutes... i guess boiling water is a smarter move! hah. but the BBQ does work. just make sure you use thick gloves.

Bam! Problem solved. Reason # 88 to be a parts hoarder.

I used the top cup from another headset; parts of it are vintage Campy Record, but I'm not convinced the whole thing is. The edges of the cup matched nicely with the race in question. I was pretty sure there was just enough play so that I wouldn't end up with the cup stuck in there. I carefully applied the headset press, nervously removed it, triumphantly noting that the cup *** drift came away with the offending gap pictured in the OP gone.

This now added to the Spaghetti Legs SOP for fixing headset screw ups.

Edit: asterisks above - notice BF doesn't like the Latin use of a word applied to an object used for another purpose.