halocline
Contributor
Therein lies the problem; 2 LP ports. You'll need a splitter to use a standard octo and an inflator along with your primary 2nd stage. The trident catalog has them. While you're at it, check to see if the HP port is 3/8" (likely) or 7/16". If it's 3/8" you'll need an adapter for that to attach a modern HP hose. 7/16" female to 3/8" male. Vintage divers use these two adapters all the time.
I know someone's going to suggest using an octo/inflator, but deciding to use one simply because you don't want to use an adapter is silly. If you use it as a pony/stage reg, no problem, you only need 1 LP port.
It's hard to tell, but it looks like it's the "middle" yoke, which means it's probably ok for a 3000 PSI tank but you might have problems going higher than that. There might be a service rating for the yoke stamped on it. If the yoke is too light for the pressure, it could bend a little which could cause the tank/reg seal to leak. It won't break sending the reg into the back of your skull.
