[zippy500]

Just came across this on ebay, says its a cartridge version, not sure how you mount it, looks like you will need a homebrew controller too.

http://www.ebay.co.uk/itm/Remy-HVH2...815026?hash=item3f898f6232:g:QbEAAOSweW5VFE0E

seems like a bargain when you compare it to this

http://www.ebay.co.uk/itm/REMY-ELEC...797644?hash=item3d1c990dcc:g:BZIAAOxyNThTcvfV