they are very comfortable and readily available.
i had this model, which i believe is the first model, several years ago when they were affordable. i also had the complete workshop manual for it in German which didnt go with the watch when it went to auction so if i find it i'll stick it in the post.
they were pretty advanced and high end for a military chrono with flyback feature and 36 hours is more than sufficient if you wind it daily.
nicely bought and good to see you've been drinking and seeing double
best
G