We know nothing about watches - these 4 came from a house clearance auction sale with other things that we wanted to buy.....We have not attempted to take the backs off of any of them.
The pictures show you enough hopefully.
From left to right - watch one seems to be working OK - it has the number 721646 on the back.
Watch two seems to be working - has a scratched plastic (?) cover. It has 552030 TL on the back and an old metal strap.
Watch three is not working - 330257 on the back.
Watch four is a SEIKO SPORTS 100 and is digital - 497164 on the back - scratched cover but seems to be working fine.
Any questions please ask - we will try to help.