I have quite a few dev carts laying around for my own use I basically don't need anywhere near as many as I have, but find I kind of enjoy making them... I've gotten to the point where I almost never even burn myself on the NES boards (the PCBs never really got burned, just me.
I'd be willing to cook some up for some forum members not so skilled at soldering and have an ample supply of donor carts and/or third party boards plus associated EPROM/EEPROMS and other chips to make them in the following configurations:
NROM
CNROM
UOROM
AOROM
MMC1 (pretty much whatever you want).
Turn around is probably about 1-3 business days (depending on whether I need to make it or have it), and I'd ask for a price of $45 to cover build time/labor, parts, and shipping to most of the world. I can work with people who are strapped for cash though, just that's my asking price.
I can also do special order boards, including MMC5, whatever. Just understand it will be a special order and I'll probably ask for more (think like $70 for MMC5). I also might have to refund your money if I simply can't find the parts, but I'll do that promptly in most cases.
All boards feature a nicely cut "perfect fit" hole for the ZIF sockets easy access, and for those with board controlled mapping, a toggle switch that toggles between H and V mirroring with labels. The carts are stripped of labels and will ship to you with nothing minus my own little logo that can easily be removed. Your free to customize.
Hope someone takes me up on this, as I'm actually finding myself enjoying the hardware part more than the software part. Guess that makes me weird?
Thanks for reading, PM me if interested.