Hi Keith,
It was a few years ago that I stripped, cleaned and rebuilt my PD carbs on my 550k3.
I recommend new gaskets for the float bowls, deffo.
I've not seen that top gasket issue with holes out of place. You may be able to punch out a new hole; and leaving the odd hole redundant (but you can judge that easily by removing a top cap to inspect the ports).
Just to share my experience with PD carbs....
I thought/hoped a thoroughly good clean would do the trick.
But alas, I could NEVER achieve a steady tick-over and always ran VERY lean.
To cut a long story short.....
I bought & fitted new Float Needle Valves,
I set Float Height to 14.5mm (both of these are a MUST),
By all means ultra sonic clean the carbs. But don't bother trying to clean/ultra sonic or solvent clean the Slow jets, they are just too tiny.
NEW Slow Jets "#42" were a MUST for me, & instantly it produced a steady tickover!
[some sources say "#38" Slow Jet, but go for #42].
Set Pilot Jets to "1+1/2 turns out" from closed.
For top-end running, I increased the Main Jets to "#95" (from #90) to cure the lean running.
I left the Needles and clip positions unchanged, middle pos'n#3
[I bought my Jets from SCI
www.siriusconinc.com - before DSS & CMSNL had anything]
One final piece of advice, DO keep the set of four carb bodies all linked together as one assembly; you can still work on each carb, alongside each other.
Oh & after many grazed knuckles, I could get that bank of carbs out and back into the bike within 2 hours! (just don't ask me 'how' now!)
Good luck & persevere!