Do you have a little more detail? Or a photo if possible.
SVS made a couple of plants: The early models were a tiny (I have one) twin oscillator with 8mm bore and 12mm stroke. This plant was originally available with a simple pot horizontal boiler or a centre flue horizontal. Later it was named the Heron with a horizontal centre flue boiler or the Vale with a vertical boiler. At the same time the Vale and Heron were available the Snipe also came along with a more sophisticated boiler design and enlarged to 12mm bore and stroke. The Snipe was a direct competitor to the Cheddar Pintail, although as I have never seen a Snipe running, I cannot say how they compared performance wise.
In the information I have, there is mention of safety valves with both 1/4 x 40 and 3/8 x 32 threads, so I would hazard a guess that the bushes will be pretty standard, but I will go and check the boiler on my early SVS twin.
As you say, SVS are no longer in business, as when Mike Legg retired the rights passed to Tony Green, who sadly passed away a little while ago. As far as I know, nobody had picked up the rights to these plants, which is a shame as they are nice little engines.
Neil
