Sorry, wish I could help but I don't know the specs of your slug to give an educated opinion. The bottom ends may be the same, but are the heads? I don't know. If they are the same through and through except the bore size, then wouldn't you be able to use any of the aftermarket cams that Crower makes for the d17?
Hmm. Where do you live in the UK? I'm in the US Army, stationed near Peterborough and have the benefit of receiving US post at the base. Dezod will probably ship to my address and he carries the D17 Crower cams.... PM me if you want and we can discuss the details.