Hi Shaun,
I may be able to give you some advice on this watch if it's the quartz model. But I need to know the exact model / cast stamp on the back and a pic would be good as well - even if its damaged. I have a feeling that the quartz chrono version is the same movement used in the Heuer 2000 quartz chrono circa 1983 onwards(typified by 2 beats per second) and this was carried over to the Tag Heuer version till about 1990ish. I have a Tag Heuer version which I may and do stress may sell to you if you are interested.
Regards
Steve