Thanks all for the quality replies

Going one by one
1- oops. Enough said
2- sounds like it's a common issue. Say there's about a quarter of a millimiter on each of the post caps (yes, they're on

) in their cwf holes... not enough for the posts to move that much, especially once the deck is tightened down, but still too much for my taste especially as it's just about machining the top deck right... I guess I'll run it like that.
3- that's the one that's really upsetting me. Ok, I'll tear the car apart again and try to figure out what's up again, point #1 was humbling enough to make me skeptical about my kit-building abilities

It IS turning, but not really freewheeling like I'd expect from a shaft car, although this is way less of an issue with the HP and capacity in the modern BL/lipo setups than it was in the good ole brushed motor days
4- yes the grub screws/oring are on. All right, I'll do with slightly wobbily cups.
Wilco if I find anything interesting re drivetrain. Thanks all
Best,
Paul
PS: no one with a 9783 for sale, then? they've been bo'ed everywhere since I started looking 2mths ago