He is from the province of Mahweet north of Sana'a , from the region of Taweelah , in a village called Bait sroor or house of sroor ( the "oo"pronounced like pool ) but it was originally a Jewish village called Bait sroom , which is probably a Jewish name , perhaps your in-laws would know . The belt belonged to one of bait sroor families, but they sold it few years ago to their neighbor, which happens to be my friends father, to finance their son's wedding . Interestingly, I just found that some of my most interesting items I bought from my friend came from that deal.
He doesn't know where did their neighbors acquire them, but the roomer goes that they were treasured in the walls of their old house and were found by accident when they added a new apartment for their said son! It's quite far fetched but certainly explains the sudden appearance of the jewelry,