Re: bigsby in tune?
I just recently got rid of an epi LP that had a stock bigsby horseshoe on it.
I got rid of it because it was a pain in the ass. That said, some people love them, more power to you!
Ideally, a bigsby should have a 'rocker' bridge. That is, the TOM has special thumbscrews that allow the bridge to actually rock back and forth as you use the vibrato. Otherwise, your strings are sliding through the saddles, and hence, they settle in a different place and you are out of tune.
Getting a super slick set of saddles (i assume graphite would do it) and a set of locking tuners should HELP the problem. But, as stated above, you're limited to light vibrato with the Bigsby, and any attempt at any big push or pull will throw it all out of whack.