Pardon my ignorance on this subject.... But assuming my recent purchases are geniune (and they can go back to H&T if they are not 馃槻) will TAG service them if there are no official sales records?
Yes. If you're sending them in for a warranty claim though you might need the warranty card. Otherwise, TAG will service any genuine model no matter the age or where you got it from.
So far its losing about 3 seconds per day, I understand that's well within tolerance?
Yes, in fact that would be within chronometer standards.
It's important to note though, that good timekeeping doesn't necessarily preclude the need for a service. If they're older TAGs, how long have they gone without service?
I think the WAN2110-0 has never been serviced or worn previously. Zero marks or scratches and still had the plastic on the back of the case. I appreciate that its going to be the best part of 10 years old and once its out of the retailers warranty I will look at getting it serviced.