I recently had plumbing job in Bristol that required the replacement of a shower cartridge, but I had problems with identifying a cartridge for a Bensham shower. I thought I would share my findings in case it helps anyone else.
The shower was a Bensham Edwardian exposed thermostatic shower, and the cartridge is manufactured by Valquest, model DC70.
DC70 comes in two versions: SDC70-T32 and SDC70-T20. You can tell which version you have by counting the number of brass teeth, so T32 = 32 teeth and T20 = 20 teeth.
Valquest DC70 model identification
Other shower makes that use this cartridge are Trueshopping and Crosswater.