Update! Due to the rain in SoCal this weekend, I had two days to work on it. I mostly finished the side walls. Took a lot of work.
Here's the Ford logo side (the red sections are for the lid to slip on top of and then for the walls to slip into the bottom tray)
I'm using some pegs in the longer side walls to attach then together. I have some ideas to also add supports to make the box more structurally reinforced. I also have the sidewalls come together where the seams are on the original battery. So perfectly will match.
Pushing them together digitally, we can see the walls taking shape.
I then put the top cover on. Starting to really look like the battery!
With the cover on, I could check the optima with the walls. Turns out, the feet WILL be a problem after all. Bummer. You can see two spots where they poke through. But only the feet and only one small corner.
Making the battery walls transparent, we can see the optima fits beautifully inside vertically, in fact, I'm going to have to make an elevated stand on the bottom tray to keep it raised up to the correct height. So that's good!
Finally, I got the .2mm nozzle for the printer and printed out the plugs again. Doubles the printing time compared to the .4mm nozzle! Took 3.5 hours for one plug... But the results are amazing. You can easily read the U.S.A. with the periods! Here is the .2mm printed plug with an original (original is left). I'll paint the new plug and it should be just about a perfect match. And it screws in still to the original case!
Next up: I need to design the tray, reinforce the walls, figure out the best way for the tray to attach to the walls for stability and strength, and then the toughest thing of all... The darn chaotic star texture on the side walls. That one I'm struggling with a bit, but I have some breakthroughs.