Bonjour Mick,
In France, we have two manufacturers, Anton and JMC, I have lot of their machines, they are perfect but expensive. As I always try to enhance my collection of boats, I acquired two Microcosm engines
The 8 cm3 slide valve :
https://www.youtube.com/watch?v=TO16806-3pM&t=306s and
https://www.youtube.com/watch?v=AOgJV8Xc7qUThe 3,7 cm3 oscillatiing :
https://www.youtube.com/watch?v=vutlswFW4X4These two steam machines operate quite well at two bars, whic is good for their autonomy and preservation.
I also have different accessories like single and double diaphragm gas regulators, pumps, tanks, lubricators,...
For me, Microcosm has an excellent ratio price / quality and I regret Jin does not build cylindrical valve engines to install them in a twin propeller shat hull because they jut need one servo to reverse.
My only concern is about the size of the boiler associated by Jin to his 8 cm3, this is why I have bought a pump to be installed in my tug to increase it autonomy.
And useful for you, less for me, Jin uses imperial measures insted of metric by default.
Last point, Jin offers impeccable and fast after-sales service (tested).