Oswald custom strat set up

Here I'm setting up Kristin's 'Oswald' Custom Strat - handmade in the Netherlands. This is a very nice Strat with relic'd nitro blue finish, giving way to an underlying nitro sunburst. There's some nice checking and some harsh chips in the finish to simulate normal road-wear. Overall, a nice looking package that feels pretty good. But it came with a pretty high action, pinging from the bone nut and tremolo tuning instability.
Kristin wanted to retain the original bone nut so that's what I set out to do. Even before I lowered the playing action, the 1st fret action set by this nut was well under my preferred minimum. But still playable. Once I'd lowered the action, it really was 'capo-level' clearance at the 1st fret. Again, playable (since we all play with capo's now and then) but SO minimal. The real challenge was widening these slots to fix the dragging and pinging of the strings without lowering them in the slightest. One mistake and I'd be finding a new nut. Mercifully I was able to achieve this leaving that hair's breadth of clearance over the 1st fret.
After that, the challenge was to very carefully level out a) some mild choke on high E bends and b) some wear grooves in the first half of the neck. This was done successfully with the legendary Banana tool; once I'd re-crowned, sanded and polished this guitar's action caused me to utter the expression I can't stand - "plays like butter" :D The only thing that wasn't 'fixable' was the tendency of the tremolo to put the strings slightly sharp if pressed down in a full-on 'dive-bomb'. A quick pull of the strings resets them to correct pitch... but there's something about the travel of the strings over this relic'd / old-ish bridge saddles that causes them to first slack, pull forward and then tug backwards, going sharp. Roller saddles would probably sort that out - and I'm going to do exactly that the next time I'm fitting an otherwise excellent bridge such as a Wilkinson / Musiclilly one.