Dave
Not all mid 20th century blades were made of two halfs welded together. This blade has a shallow diamond shaped grind to it and not a raised forged rib as seen in the other example. So this blade was probably made via stock removal. As far as I know Arabian,Yemen and Omani jambiya were never etched they always show a high degree of polish. This blade looks as if it was purposely etched or over etched to give the blade either a wootz look or at the least an older look. This seller often comes up with blades that have been recently etched just to show off a particular pattern even if it's shear steel so he can say it's damascus. It's like using the Zulu term on any African piece it seems to stir up higher prices
people here the word wootz and they start to flip out. It's like Sy Syms always said "An educated consumer is our best bet"
Lew