GB707's are finally installed; I made time and room on the workbench to finally do the fret level and crown I was waiting for, which turned out to really be needed. Several frets were WAY high. Now have low and buzzless action with about a 0.010 neck relief, which is better than par for a shortscale. Stock bridge is very nearly all the way down.
The 707's fit with only minor sanding of the post holes. Mainly needed paint cleaned out of the holes as they are more precisely sized than the stock tuners. method used was an automotive deep socket wrapped with 320-grit paper, and a little care to keep everything round and true. Took maybe 5-10 minutes per hole and ended up with nice snug fit. Screw hole was fine as-is, and I reused the original screws.
The posts are much larger in diameter than the stock tuners, which shifts the north-of-the-nut string alignment a bit, but not problematically so. It also means strings should be cut longer, but I was able (barely) to reinstall mine which had been done with an Ernie Ball wrap. Leader kinks may be robbing a little sustain, especially on low E. I may have to bite the bullet and get new strings but money is money. I will work on smoothing the leaders. I only got 2 1/2 wraps at most on the post.
The only downside to the GB707's is that they are noticeably heavier than the stock machines. Otherwise they look and work great and do fit with only minor clean-up. Tuning is wonderfully smooth and precise and they hold it well. I think they look a little better, too.
I got them very inexpensively (they were on sale, less than $40 as I recall) but if I decide the weight penalty is too great I may bite the bullet and get a set of GB350 Res-o-lite's instead. About $80, aluminum machine and plastic buttons, and way lighter.
$50 strings and $80 tuners seems in one way a bit rich for a bass I spent $180 on... but it now plays as well as anything in the $1500 range, with a little elbow grease. And gets that wonderful hollow-body thump.
And with the custom plastics I made, I think it looks way better than the ~$300 I have in it, too.