+1 I am a fan of the Sheldon Brown method. If I am thinking right, you will have to access the bolt from INSIDE the bottom bracket. So I would use a socket, a short extension, and a 1/2 inch breaker bar. I would soak with Kroil a couple of times. If that did not work, I would bring heat into play, and still use my breaker bar. Once the cup is hot, I think it should come out.

While trying to avoid the incoming storm I'm going to throw my own few tips out there.

I have had good luck with actually bathing the BB are in something like diesel or kero. Penetrating fluid works wonders if its immersed in the liquid.
Get a blowtorch at it. It is the only thing that will ever remove red loctite. Its only broke down by heat.
Leverage. And lots and lots of it. I've a 5ft pipe that goes over my spanner that I use for BBs. I've yet to be defeated by one.

And the var tool looks awesome. I want one.

I'm gonna go ahead and lock this thread so you folks have some time to think about what you've done.

Ok, now that you've all had time to think about what you've done I'm going to open this back up. HOWEVER, if I have to come back there again not only will you all go in time out, but all of the bike frames and Thomas trains are going in the trash. You've been warned.

So... When did they make you a moderator, Holiday?

1976, if you knowwhatumsayin'.

I've removed both fixed and adjustable cups of both Italian and English-threaded bottom brackets using the Sheldon Method and it's never failed me. I recently removed one that the lbs tried all their tricks on and gave up as hopeless. I use a longer bolt with an extra lock washer and marinate the cup for a couple of days then it's just a large crescent wrench for one side and a socket with a short extension and breaker bar on the other. I'm no mechanic and can't claim any experience loosening anything with loctite, but this method has never failed for me.

Heat and vibration are your friends.

I spent 20+ years working on the rustiest salt-damaged Pennsylvania vehicles known to exist, Volkswagens. Before attempting to twist the cup from the frame, it helps to fracture the corrosive bond by hitting the cup with a hammer. Not just once or twice, but maybe 100 solid hard hits. Applying heat to the bottom bracket shell will also expand the shell and break the bond of any corrosion or Locktite. One should take precautions with the finish if saving the part is a concern.

The vibration from an air chisel will also loosen tight parts. Chisel the part in the direction it needs to loosen. The chisel will dig in and mark the part, so that is a concern if the part is to be saved.

Does everyone in this forum break a bike or frameset down to it's last individual parts before they sell it?? BB cups, Stems, Seatposts and even waterbottle bolts all sometimes end up siezed on frames and many never even know they are siezed, even for many many years, especially if the previous owner(s) never had a reason to take them off to adjust or replace them. Lots of us have bought bikes with these problems and usually take it as a matter of fact risk of buying any used bike or frameset and just deal with it. Afterall, a bike is mechanical and there is usually a fix for most problems that come up, otherwise, maybe a person shouldn't be messing with C&V bike resto/builds if they can't handle the challenges that come with it. I think it was a cheap, low blow to attack Kurt and/or Stausy for this stuck Italian cup. And kudos for Kurt for offering a full refund if for some reason, this thing could not get fixed. You can hardly expect that from many sellers out there these days.
Maybe if you are buying a brand new bike from a dealer you can naturally expect such as a warranty claim, but certainly not in the second hand market/private seller scene.

As for the stuck cup on this partucular frame, a good point was made about trying to preserve the existing threads under that stuck cup as much as possible, as the larger Italian treading can maybe be chased clean, but cannot be replaced with any other threading anymore without re-building up the BB shell material. It's been done, but it is a specialized and labor intensive process that most likely, only a frame builder can handle.
Going all "gorrilla" with the cup with uber force or impact might endanger the frame's integrity too, so you have to know when to give up and go for cutting out the cup instead, to avoid "collateral "damage.

Chombi