I found a heavy black leather HP case in a thrift shop. It holds a 42S in its slipcase quite nicely, but it was probably not intended for that.
Flip-over top with a push-though snap closure; about 6.5 in. high and 4 in. wide. Two 4-in. long belt-loop slots on the back. (That's about 16 cm x 10 cm.)
Does anyone know what it was for?