I suspected as much...

Then the only other real option is to go with a crankset/BB combo.
Another consideration is chainring 'spread'. An Ultra 7 is prolly set with more distance between cogs than the newer 8-9-10 spd cassettes (assumption...) and now that I'm on my last Sedis Sport chain from the stockpile I put away over 12 years ago, I'll be needing to buy a new chain.
I'm clueless as to what chain will work with freewheels and still shift okay on the front, if that might be a consideration.
Might I have to 'shim' one of the front rings to make the 'compact crank' compatible with the older cog spacing? What chain might give the best opportunity to make this all work?
More recommendations are really welcome here.

20 years ago I was on top of the tech side of cycling. Now I feel like a 'vacum tube' engineer in the age of nanoprocessors.

I'm not hanging onto the old steed cause itz so 'special', or as some statement of 'retro' or individuality.
I'm staying with the 'not-so-old' machine cause it fits me purrfect, is a joy to ride and offers no real reason for me to abandon it. It has served flawlessly for 12+ years (4 of which I didn't do any cycling at all). So flawlessly that aside from a new freewheel, a few cables, a few chains from my stockpile, and regular new rubber, I've not had to pay any attention to replacing parts. Its reliability is probably the reason I've not even looked at newer tech stuff.
Anyway, I need to get the lower gearing and the 'compact' - 50/34 gearing spread is exactly what I need. I imagine I'll eventually break down and retire the Campy LF hubs, spread the rear (of the bike) and get a new wheelset or 2, but that'll be hard to do. I may not go up hills like I used to, but I almost never lose a coasting contest on those wheels.

Help me Obi Wan, you're my only hope