Scubapro was not then nor now stupid. They did a switcharoo for example on the clocking of the air barrel for the G260 so that it could not be used in a G250 thus forcing us G250 fanboys to buy the G260! Dang them. And I have found it true that the threads on the bodies and covers can differ model to model to prevent such franken-regs. But I am not expert enough to say a combination could not be finagled or forced together. I would not give whoever much for what appears to be a parts reg.
Now here is a R190 with Jetstream mate on a Mk V:
Sometimes with this set I cannot decide which is primary. That is what is cool about the 40 inch hose. Whichever can be primary, one standard octo rigging, the other choice long(er) hose primary. All I have to do is to move the neck bungee to the alternate . Because sometimes I feel like a nut and sometime I do not. Blows my mind!
Now here is a R190 with Jetstream mate on a Mk V:
Sometimes with this set I cannot decide which is primary. That is what is cool about the 40 inch hose. Whichever can be primary, one standard octo rigging, the other choice long(er) hose primary. All I have to do is to move the neck bungee to the alternate . Because sometimes I feel like a nut and sometime I do not. Blows my mind!