After a discussion with guys from Sweden times ago, they told me SEM buy their small cylinders from L&S in France. (need to be confirmed)
So if you need more infos drop a mail to:
commercial2@ls-france.com
Or call :Tél. +33(0)5 59 56 26 46
They are able to communicate with you in English, Spanish, German, Russian,French.
The guy in charge of these cylinders for competition is Thierry ETCHETO
The last prices/references I've got for these cylinders inside diam 32mm/stroke 181mm are :
designation : 2 racing cylinders bore 32mm stroke181mm
reference: 2210007
price without VAT :504€.
In added pictures these small cylinders installed on a 300 VMAX for informations.
you can ask them built in steel or in Aluminum...
Hope that helps.