Pleased to hear that yours is still going OK, just keep an eye on it.
I had look at CBS this morning, and they have many more options than last time I looked, though they only seem to have 1 that suits 1/2" Hose, all others suit 5/8" hosing;-
This is the only 1/2" one:-
http://www.carbuildersolutions.com/uk/12mm-12-heater-valve (i have one of these in one of the cars and works well, but not always convenient)
These all suit 5/8" Hose. but you could use them with adaptors;-
http://www.carbuilde...ss-heater-valve
with this perhaps (although a standard Mini one would also work I think)
http://www.carbuilde...alve-controller
http://www.carbuilde...on-heater-valve
http://www.carbuilde...ss-heater-valve
http://www.carbuildersolutions.com/uk/solenoid-operated-onoff-heater-valve (I'm gunna get me one of these)
http://www.carbuilde...58-heater-valve