Bonjour,
I woudn'nt have imagined so many reactions to my post. As French collector, I have always built my steam plants with metric measures and bought my accessories to Anton or JMC (
https://www.jmc-vapeur.fr/) Especially, the first one offers a 2mm piped gas line and JMC a 3 mm one.
Based on the prices I know, as I guess resellers take their margin, when I recently discovered Microcosm, Jin's products were almost half the price of my Frebch manufacturers so I tested him. Objectively, the quality is not equal but is worth its prices.
Examples :
https://www.youtube.com/watch?v=FDF7jQmvvRo or
https://www.youtube.com/watch?v=TnNkqDPZnWwBesides this, I fully understand and agree with John, all these accesories are not mandatry at all... but to my opinion, as they exist, they are reassuring.
One of my first boats had not a RC safety gas valve, a leaf blocked it in the middle of the basin, I went to get it barefoot and ended up in the hospital after stepping on a shard of a bottle
I do not know if Anton goes on building or not these accessories, if you would be interested in one pg them, you would contact him, I am not at all in his business !