Bevan, I spent some time trying to find a suitable compressor to suit a VB side valve until I changed my internet search criterion to look for a motor mower one.
The normal home push mower one will be too small but I found a couple suitable for early ride ons that fitted my VB nicely.
Most small engines now are OHV.
1946 VB600 rigid Tele
1933 Austin 10
2008 Fraser Clubman (like lotus 7 only better )