[GZG] Shrinkage question

Hi, Looking at the NSL SDN and CVH got me thinking about maybe(if ever)
doing some alternative engines or front-to-back connectors, and then
replicating these in resin. Measuring them, it seems the engine connectors are
3mm and the
front-to-back connectors 5mm, which are probably standard sizes.
Would there be much shrinkage if I try to replicate some homebrew styrene
thingies in resin, or shouldn't I worry too much about it?

Frits

P.S. For the IP police here: I want to make some compatible things that work
together with these models, not copy any of Jon's work. And I want to do this
for my own use. If this ever comes to anything and other people are interested
it'll be up to Jon how that should be arranged.