Waltham was an american watch company in the early 1900s, and wouldn’t have started making wrist watches till after ww2, and more realistically probably the 50s and 60s. I have a mechanical wrist watch of theirs from the 60s. At some point they basically sold off and basically became a brand that was put on watches other people made. This looks like one of those generic watches that they put their name on.

If it was gold plated, or for the 50s-60s era “gold filled” or “rolled gold” it would say so on the case back or edges of the case. Something like 14kGF etc. If you open it up there’s probably a model or movement number on the mechanism inside, and possibly details about the inside of the case back.

If you’re in the US, there’s some up on Shopgoodwill, though they don’t always list model information. Might be worth setting up a saved search there too: https://shopgoodwill.com/categories/listing?st=fossil%20big%20tic&sg=Keyword&c=&s=&lp=0&hp=999999&sbn=&spo=false&snpo=false&socs=false&sd=false&sca=false&caed=11%2F14%2F2023&cadb=7&scs=false&sis=false&col=1&p=1&ps=40&desc=false&ss=0&UseBuyerPrefs=true&sus=false&cln=1&catIds=&pn=&wc=false&mci=false&hmt=false&layout=grid&ihp=

Of course there’s minimal details on quality and if they work, but if you’re lucky you’re the only one looking for them and can get them for less than 20 bucks each. Just make sure to estimate the shipping as it can be surprisingly expensive on there.