I bought the watch new from an authorized local dealer around 1989, and it's an early stainless case 28mm F1, blue dial/bezel, stainless bracelet. I'd like to have it serviced, but TAG USA's form online asks for the serial number and reference number from the back, but it has no such numbers. Suggestions? It needs a battery for sure, and has never been serviced. Hasn't worked in years, but worked fine for ages. Can I get the crystal replaced (it has some scratches and a small chunk missing along ghe outer edge, and I'd like a new dial and bezel (black, rather than blue). Will this be crazy expensive? Thanks.