So I've made some progress, and the engine is in. Required a few modifications for clearances, but not much:
https://youtu.be/VqekO_9Z_pwNow I'm looking at radiators and front-mount intercoolers. I'd prefer to get an off-the-shelf item, but for the intercooler in particular that's looking difficult. I'm planning on using an aftermarket Datsun 1200 radiator, which sounds like it won't be enough, but it has a much higher volume than the original starlet GT radiator, and very similar to the half size aftermarket radiators used for larger turbos in the same car (radiator isn't as long, but extra cores).
I was thinking about using a Discovery 200TDI intercooler, as it fits nicely under the bonnet catch. It is however a little too long. Another option is an MR2 intercooler, but that is 100mm thick and will hit the turbo outlet. Even the Discovery intercooler might require the grille to be modified for space. So I might end up going down the custom route.
If anyone else has had a custom made intercooler I'd be interested to know where, and how much it cost.
Another snag is the oil filter. Most filter relocation kits attach to the bolt-on oil filter mount, but even my mount doesn't have the clearance. I'm not sure if I can just fit one to mount like tricky has (seen in his post here:
viewtopic.php?f=23&t=22654&p=896317#p896317) or if that is a custom made job. If I can fit a regular mount there, I can feed the turbo with a t-piece from the oil pressure sender hole.