Identify my watch please

I recently acquired a Tag watch from my great aunt that belonged to her son when he was growing up. Im almost 100% certain its real because they were well off so I dont see them buying from anyone other than Tag for the watch. I have the case, all the original links, the pillow, and of course the watch. However, the manual is missing so i cant identify the actual watch name and just want to do some research to see what I have here. I dont currently have the watch with me as its at the jeweller getting a new battery and cleaned up but i have a picture of the face. Could you help me identify me the model please? Thanks for your help

It's a well-worn early second generation F1 Chronograph.
http://www.calibre11.com/overview-tag-heuer-formula-1/3/

Thank you. Yeah the guy wore it from when he was 9 until he graduated high school and got a new tag watch so it has seen a fair amount of wear.

TBH if you managed to get a replacement bezel (perhaps easier said than done) it actually wouldn't look too bad at all.
Is the lower push button missing? That's more of a concern.

Yeah unfortunatley the bottom button is missing. And I think that would do it some good if I replaced the bezel and the button. It also needs some buffing around it but thats why its at the jeweler right now. Im not wanting to pour a lot of money into it because I plan on using it as an every day wear watch so it would end up getting its share of scratches anyway. Ive also got a black fossil defender from the 80s I wear around daily right now I love. Do you have a price estimate on how much a new bezel and replacement button would be

If you can find the correct bezel, I doubt you'd get much change from £80.