The #Simple Universal Modem got a reasonable Top 50 finish in the 2022 Hackaday Prize but I didn't have a way to sell and ship PCBs.

Thankfully, now I'm shipping enough #65uino kits that there's no extra hassle with also offering PCBs for the modem.
Only PCBs available for now (price 2€ + shipping) - I can make full kits available on request. 

https://www.imania.dk/index.php?cPath=204&sort=5a&language=en