However the scabbard are of a souvenir-kind, people don't wear in Yemen scabbard of this particular style. They should have a loop at the backside to hang them on a wall.
A one on the left shall reproduce Gusbi style of southern Hadramaut, the right one is called Tuza and jambiya of alike style was historically worn by nobles, judges, etc.
And one more of the same pattern shall reproduce a one worn by tribesmen and ordinary civilians
But again my opinion is that all three jambiya's scabbard are souvenir, while the blades are just the same as worn by yemeni men.
Sorry for my english, long time no practice