I have a Sherwood Oasis that had the same first stage and the second stage is of similar design and I know it's from the late 1980's. I have upgraded the first stage to a newer Sherwood dry air bleed with the externally adjustable ip.
I still use it and it looks and works great after almost 30 years of use. Very easy to maintain and it breathes very well when adjusted correctly. I had a Sherwood Shadow integrated octo that came with it but I sold it to buy an AIR2. That was a mistake. I think the Shadow is a better integrated octo and it can be used with any standard bc inflator. Those Sherwoods are so simple in design that they are practicaly bullet proof and a drunk monkey could service them.
I have a collection of regs. Actually it's more like a hoard. A Poseidon Cyklon and a Jetstream, several SP 's mk2, mk5 and mk10 with 108 and 109 seconds, several AMF MR12's, MR12 II and a Mares MR12 III, several different USD Conshelfs and Calypsos to name a few. They are all excellent regulators by any standard. But to be honest I find myself grabbing the Oasis to go diving with more than any of the others because it is so easy to set up and maintain compared to the others. I like a reg that I can access the second stage diaphragm without tools and that I can adjust the ip without taking the first stage apart.
I think a lot of the people that badmouth Sherwood either never actually tried one or they didn't have one that was tuned correctly.
Sherwood is probably the largest valve manufacturer in the world for just about every industry there is, from beer taps to aerospace applications. They actually make the valves and regulators for a lot of different scuba equipment companies that just rebrand them with their name on them, like the Poseidon Jetstream, which is just a rebranded Sherwood Ultima.
Sorry about that, I kind of went off on a Sherwood rant there.
