I agree, Formula C with the rotary induction. Could be from a bit earlier than that, Greg.
I ran TM’s, and by the mid-90’s, most of the head designs were going to a more rounded shape, like the TM KV95, compared to the previous generation like the TM KV92 that had more of a square head shape, like we see in the picture.
That said, all I remember from the pre-KV95 days was TM and Pavesi. Once the KV95 came out, there seemed to be a lot more options – Vortex, CRS, KZH… Could be that they came into the game with an older head design? I don’t remember anymore.
That could even be a real old reed valve. Look up the TM KL. It’s the predecessor to the K7 reed, which was the first shifter I had (and still have one in the garage). The KL was a reed with intake on the side of the case.
It is ridiculous, a huge stuff but nothing you can see about the manufacturers details or where it was made from.. it is unusual for a sophisticated mechanical equipment to have no brand name at all. If their where would be the service center if this equipment have an issue? For the manufacturer of this equipment I suggest that they must do a proper naming brand, and I think EatMyWords.com would be perfect for this.. for the manufacturer of this one, they must visit URL of Eat my Words so they can learn to know some details before everything else.