My wife got ill so I was managing a toddler solo all week, so things have been moving slowly. But I finally got a little bit of reportable progress.
Got the cup repainted, so that's good.
The photo box has been cut down (CORRECTLY this time) to 2.5". I've been thinking about pack mounting options, and decided to use the lid plus some reinforcement. I cut two sides of the lid down so it fits perfectly inside the box. Two edges of the lid's rim (minus about 1/4") will fit flush inside the box, and I'll add a couple of cheap L brackets in the opposite corner. I can glue inside the box rim to the remnant of the lid rim, and that will give me a very strong full-length connection on 2 sides. I'll use a strip of strap wood inside so I can mount the lid (as a backplate) REALLY firmly to the oil pan.
With that worked out, I went ahead and glued the radio faceplate on the box with e6000, and screwed in the corners. (I decided to use #8 machine screws with nuts, instead of the #8 sheet metal screws Ukswrath had used, since this 2-part printed faceplate really needs to stay in place firmly.) I even got a coat of paint on it!
I'll add another coat of paint before calling this done, but we're very nearly finished with this part.
I cut the new backplate for the arch box. (sorry, no photo yet) I used the self-adhesive floor tiles I had originally purchased for this pack. I took the warped 3D printed plate, and just traced around it and cut out the new plate. Worked pretty well, I think. I touched it up on the bench sander, and slapped on a coat of paint. Assuming it looks ok when I get home, I should be ready to glue the arch faceplate on it, and attach it to the tupperware, and we'll have yet another piece done!
Next steps: I need to:
Sand and paint the radio box faceplate
Cut the picture box shorter (or make a box!), paint it, glue on the faceplate
Repaint the cup assembly Clean off the labels/logos and paint the baby wipes canister
Paint and glue the rubber bumpers
Predrill and rivet the gray cup to the black faceted cup
Add the top screws to the three faceplates where needed: Radio Faceplate, Button Box, Arch Box
Cut the ends off the tube end caps and get that all glued together, with the TK shoulder strap part.
Cut out the oil pan opening and remove the screw top, since I guess we can't use the antennas anymore? Bummer, since I bought the antenna.
Scuff up the bare black plastic of the oil pan
Attach all the various parts to the oil pan. (Gotta look into how best to attach them... I'm thinking nuts and bolts, so components can be swapped out easily as/if needed.)
Attach shoulder straps