Okay, here's an update with the armholes and shoulder pads. This has been interesting.
Well, first of all, I started sewing on snaps for the front. They might be temporary, depending on what I decide to do based on feedback from my last update. I think I would need stronger snaps than these anyway. They're vintage, though. I can't believe my mom still had them, as in, hadn't used them yet. But now I can use them. Thanks, mom. <3

For some weird reason, I sewed a square when I first started. Then when I realized something was off, I did it the usual way.

Extra reinforcement I guess.

Then I worked on a pattern for the shoulder pads.
First attempt, using the shoulder pad insert and pauldron pattern:

Fabric empanada! I found the edge with chalk for when I'd cut it out.



I decided I didn't want the armor piece hanging over the edge that much.
So, second attempt, leaving plenty of room for a seam allowance:


Similar length to my t-shirt sleeve. I took that as a good sign.

Sewing it together:

Turned it inside out.

Inserting the shoulder pads. I removed the velcro to use for something else.


Lots of experimenting with attaching shoulders to the vest:
Right side to right side

The spider does not approve.

The pumpkin is giving encouraging comments.

Seeing how the proportion looks with the helmet

I decided not to fold over the raw edges of the vest, because that would make it all tighter than I wanted. So I did an experiment and it mostly worked. I don't have a lot of experience with sewing sleeveless tops, so this has been a challenge.

(Sleeves are enough of a challenge for me though...)
I took a sleeve pattern from one of the other cuts in the same pattern packet. I pinned the pattern to the arm hole to make sure it would fit before attempting this. Then I cut out that edge.

Then I traced the same edge about 2.5 inches down and parallel. I did have to modify it though, because it didn't end up being 2.5 inches all the way along the curve.

Pinning together and sewing:

Made sure the fabric strip would be wide enough to fold over.

Sewing

Folding over

Had to cut some darts to make it go with the curve at the top of the shoulder

Ta daa! Not the most professional job ever, but it holds together.

More experimenting with the shoulder pads placement:



Looks like my hair needs a trim. Either that or another method for pulling it back and out of sight. So far I've just been using a headband to keep it out of my face. Any ideas? Also, the flight suit top is a little bulgy between the vest and belt. I'm going to try to make the waist of the flight suit of the pants high enough to cover that, and then cover the separation between the two flight suit pieces with the girth belt and utility belt.
As for the shoulder pads, I think they could work like this, just a little more even with each other. But again, I kind of prefer they're not protruding so far out. I'll keep experimenting.