Hello I have done my OEM 12VDC 5W LED bulbs, locally in Ecuador, I am located in Guayaquil.
If you need help with DC LED lighting, I have now a lot of experience with LEDs lighting both DC and AC.
I will try to attach an image.
Here another photo of my first DIY panel in plain sun at 14:00 h (18V out).
The fan you see there is a 24 V cooling fan and it spinns from 6:30 to 18:30 h (Wow, 12 hours) when connected.
I took the decision not to cure this one with Sylguard (anyhow I have 8 more panels to built) as it will be a test panel for other additional aplications and measurements like heat inside etc.
I'm just getting started with solar, and appreciate your project post.
I agree that building your own panels is not cost effective, but when your in remote areas, any power is better than no power.
I enjoyed reading your post, and can see the Engineering background in the details.
Hope your still posting here.