I believe this is a 1965 Brigadier. Both movement and case back are stamped M5. Case is 28mm by 28mm (excluding crown). Cool looking watch that runs great!
Agree with Brigadier, similar watch

Nice watch Dane, I like this one a lot. I agree that it's a Brigadier.
In reply to Nice watch Dane, I like this by Geoff Baker
Thanks Geoff. My dad pretty much replaced every expansion band, but he kept them all in a box that I'm going to dig through and see if perhaps the one for this watch is still around. I saw it on the other Brigadier and that is a nifty band!
In reply to Thanks Geoff. My dad pretty by Dane K
What a great family heirloom!!! Looks like your Dad didn't wear it enough to need to replace the bracelet. Its in great shape. That would be cool if you did find the original bracelet in "a box".
I agree w/ Brigadier, but wonder what the ad text means by "small second hand"?
Agree with Brigadier