@beric has made some really good points here. It’s worth really thinking up front about what kind of pack you want to make. Do you want it to be authentic and “in universe”, like it’s from one of the films, or do you want to take in a different direction and do something more custom and unique to you? Plenty of people do the latter, but if you want to go the authentic route, then it’s really worth thinking about how a "real’ proton pack would have been made originally and then how it would have aged and accumulated wear over time, something I’ll come back to.
But to loop back and try and answer some of your original questions:
Should you prime/paint the body? I would say no. You’re not the first person who said the 84’ pack looks “plasticky”, but I think if you repainted it, you’d probably still end up back where you started. When I did my Spirit pack, I had to respray the whole body because I’d replaced much of the body shell with 3D printed parts, but it was a load of work, not easy to get right, but even when the full respray was done and the pack was completely matte/satin black (before I weathered it) it basically looked exactly the same as the new 84’ pack does now. It’s the weathering that can make the difference.
Should you upgrade to original brass elbows etc? I would say yes. It’s a small detail that actually makes a huge difference. Hasbro needed to keep the costs down somehow, but the hardware on the pack is probably it’s weakest point. It just looks cheap and rubbery. I have seen people try to paint them with bronze/copper paint or Rub n’ Buff, but I personally think that nothing looks as good as real metal.
In fact, in terms of a checklist of weak parts/areas to replace, it sounds like you’ve already got most of it, but here’s what I focused on:
- Brass elbows/legris
- Hoses
- Stickers
- Clippard valves
- Dale resistors
- Shock mount
- Ribbon cable (hard to find 84’ replacements though)
- Aluminium ribbon cable connector
- Lenses
- Strain reliefs
- Screws/bolts/washers (I chose black with copper washers, screws or M-type bolts)
Then it comes back to weathering and using stuff like Rub n’ Buff etc. This is a really important point, and something I’ve given a lot of thought to. Rub ’ Buff is great as it’s fun to use, easy to apply, and gives good results quickly. But I also think it’s easy to fall into the trap of ‘over weathering’ and just smothering the pack with it, to the point that it can end up looking more like it’s just been heavily dry brushed with paint (which it basically has) than actually worn and weathered.
That’s why I’ve started to think more about weathering in terms of how a ‘real’ pack would age, and I like to think about this like a spectrum.
One one end of the spectrum, you have GB1/1984 when the packs would have been fresh built by Egon/Ray etc. They were probably meant to be ‘made’ out of some kind of silver metal (aluminium or steel, I’m not sure) but painted satin black, with perhaps some very minor ‘workshop’ wear like minor scuffs/scratches.
Then on the complete opposite end of this spectrum, you have Afterlife, where the packs are nearly 40 years old, have suffered lots of wear and abuse, but have also been kept in an old barn and accumulated lots of dirt/grime/dust etc.
It then depends where on this spectrum you want your pack to sit. Do you want it be closer to the fresher/cleaner GB1/GB2 end, or more towards the heavy-weathered Afterlife end?
Even then, with the weathering, I personally think it needs to be considered, layered, i.e., use washes of greys/blacks/browns etc, but also use it sparingly, build it up gradually, and really think about how paint that’s been applied to metal would actually wear off?
Also, think about how you’d remove it if you end up with results that you don’t like, i.e., make sure you have some rubbing/isopropyl alcohol and magic erasers to hand. If you had painted the body, then applied Rub n’ Buff, then tried to remove it using IPA, you’d probably end up with an awful mess, but if you just apply the weathering to the black plastic shell, it should be easier to bring it back if you do mess up.