Rather than make something specifically for the Funkey, I looked at existing containers and cases that would be the right size. The Funkey is 42.5 x 44.5 x 13.8 mm I found this leather earphone case (60x50x25mm): https://www.amazon.co.uk/dp/B07PMCDVTD/?coliid=I1BI13H82XC4O2&colid=F9PWAXPFCJP6&psc=1&ref_=lv_ov_lig_dp_it And this metal tin (70x70x23): https://www.aliexpress.com/item/4000077615204.html?spm=a2g0o.productlist.0.0.95e37d021Fdh2a&algo_pvid=55867758-978b-4c81-a462-f6737c52bda0&algo_expid=55867758-978b-4c81-a462-f6737c52bda0-10&btsid=0b0a0ae215955930596075139e7e84&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_ The tin has enough room to add foam padding to really ensure it stays safe. Feel free to share anything else like this below.
maybe A54 here (50x50x18mm): https://www.aliexpress.com/item/32859689704.html?spm=a2g0s.9042311.0.0.2edf4c4dLuaKRy
The leather case looks good. Douglas Barros apparently found the same on AliExpress : https://www.aliexpress.com/item/32906960345.html
Currently cheaper from this seller :
https://www.aliexpress.com/item/4000430402825.html
The A54 plastic box is a great find, but it has rounded corners, so we need a try to be sure that the Funkey S fits in.