Best starting point will be once your pictures are uploaded, and always good to see another Monnin.

I will say that possibly your recollection on when you bought it may be a few years off. It wasn't until 1978/9 that Heuer entered the professional diving watch business, with these first Heuer branded 844 being produced by G Monnin, and then only for around 1 year. So maybe you're younger than you think? :)

Stewart over at Heuerville is an awesome guy and has a head full of Heuer info!

On another note the quartz 844's are quite a bit more rare than the automatic versions, so for me your watch has some added coolness. Should you find something wrong with your watch at any point reach out to the community as there are a number of watchmakers with lots of experience on the Heuers that can be recommended.