I have (a different) one, someone got sewn in heavy Canvas.. came with Brommy1 a Mk2 3T used buy..
it would serve in a Checked luggage air trip.

there is a small shop on Pier 39 that sews things Here.

And a friend in PDX that does custom Marine Canvas Work, for Sail and Motor boats projects ..

Sewing machines are useful tools .. just get someone with one to make what you need..