Danny.
Further to John's response, it seems that only a small number of SV-4A's were manufactured prior to production ceasing in 1940 and was restarted in 1947.
I have the SV-4 and variants on my "to do" list just now.
There were several licenced manufacturers, Stampe & Renard, SNCAN, AIA, SAAMR, etc.
I think we will probably list them all as Stampe-Vertongen and possibly add a comment to profiles re licencing.
Malcolm.