Hello MrInfernal and welcome to

Modding is fun, and maybe as a suggestion (before you take apart a SwissChamp), maybe have a go at a smaller model? By all means, rebuilding a SC is not overly challenging, but there are lots of subtle aspects to the rebuild that only become obvious once you've built a few, especially if you plan to peen together again (which I believe is still better than screwing).
Replacing the scales with thinner material is fine. I've done both Aluminum and Brass. Just note that newer SAKS have a pressed spacer in the outer liner, to compensate for the thinner main blade tang. So you'll need to add a suitable brass washer if you have this thinner main blade. Also, make sure your pivot holes match exactly the correct locations, as this has a big factor on the spring tension.
The spacers are functional for not just keeping clearance between the tools, but also strengthening the SAK. Some tools can work without spacers, but I'd avoid removing any next to the scissors as you'll probably get snagging. Best to do a test fit without the spacers before you commit to anything.
The awl is about 2.0mm vs the chisel (1.75mm) and fine SD (1.72mm). These dims vary over the years, but the point is that you will need to file down the awl a small amount to get to the same width of the tool you're replacing. If you do drop it in another slot, the awl tip does sit a little lower, as the backspring profile is different, but you can still get to the nail pick. Again - best to play with this before committing.
Good luck with your mods - we look forward to seeing the results!
