Size comparison

[mrnorberthorvath]

Just a little show and tell, I hope it will help somebody. I have built 3 versions: one with full header+socket, another with header on the pico, but soldered onto the board, and the third is soldered by the edge pads. I tried to take photos of the heights, because the C64C cases have very little space even without the hard metal shield. Making the "low profile" version was not difficult, I cut the legs on top, sanded the remaining sharp cuts, stuck 2 layers of capton tape and soldered the pico. If anybody needs a more precise measurement, just say so.

[frntc]

Nice comparison! You can even save a bit more height when using low-profile pin headers, e.g. https://www.lcsc.com/product-detail/Pin-Headers_BOOMELE-Boom-Precision-Elec-C9742_C9742.html

(on the GitHub-page of the Teensy-based SIDKick you can find more links)

[mrnorberthorvath]

Yes, there are still many combinations I haven't tried, and I still have 2 more PCBs at hand :)
Another idea was given by an Adrian's Digital Basement video, where he uses extra long pinheaders. Make a sandwich of the 2 PCBs with a piece of insulating plastic in between and solder them onto the middle of the long pins (one from the topside, other on the bottom). This way I can control the length of the pin on the underside, and cut the excess (and the socket) on the top, in the end only the pins remain. I am not sure if it will be sturdy enough for multiple inserts and removes, but might be good for a permanent install.