Need advice on Swan neck replacement for Omega 551

Hello all and good morning,

So, I have a lovely Omega Constellation rail dial that I got a good deal on BUT it needs a new regulator screw (the screw you turn to adjust it, as the one on the current balance is broken off and stuck in place. I came to the conclusion that finding the replacement screw and removing the stripped one would be difficult so I thought I could just replace the whole swan neck part of the balance wheel. Is this easy to do?

Most importantly, I have found many complete balances for sale but all of the swan necks have a ball on the end of the curved neck.... however, multiple people on ebay have told me of the following :

"all family 550 560 and 750 have the same balance wheel.

family/generations:
automatic:
550: 17 jewels
551: 24 jewels, chronometer
552: 24 jewels
560: 17 jewels, date
561: 24 jewels, date, chronometer
562: 24 jewels, date
563: 17 jewels, quickset date
564: 24 jewels, quickset date, chronometer
565: 24 jewels, quickset date
750: 17 jewels, day, quickset date
751: 24 jewels, day, quickset date, chronometer
752: 24 jewels, day, quickset date "

However the swan neck portion on my 551 is definitely different than some of those movements as it does not have the "ball" on the end of the curved neck. Is this truly interchangeable despite looking different? I am skeptical and have included pics. Any help would be appreciated, including advice as to whether this would just be a simple cheap repair for a watch maker and I should just leave it to them.

Many Thanks!

The swan neck with ball, for Connies, appears towards the end of the 60s.
I have it on 564s (but not all 564s)
it may have appeared on late 551s but definitely not on one of your era.

Thanks for all the help! I should have come here sooner as my search for that screw and swan neck separately had me going insane!

The part arrived today in the mail. Again, I can’t thank you enough. I’ll see you when I eventually do my road trip to Alaska!

Cheers!