My thanks to https://www.pinterest.co.uk/passamezzo/instrument-cases-15-17thc/ For some of the below ideas or images
Engraved Italian portrait from 1510, Suonatore di viola da mano, of Giovanni Filoteo Achillini (1466–1538). By Marcantonio Raimondi, after a lost original painting by Francesco Francia.
So larger, but still, a good idea for a hard case.
From https://gallica.bnf.fr/ark:/12148/btv1b69534380?rk=21459;2 – image only
Currently for carrying the guitar while walking around I am wrapping it in a rectangle of wool and placing that in a shaped net bag I made out of hemp. This temporary solution is working well.