This speaker was one of four, now only 3 left, I have a pair for sale (see my other listings) and this one without the plastic creamback cover - It’s a very nice sounding speaker – louder than the G12M and more ‘boomy’, but less compressed and more fluid. Strong in the upper mid range.
T1217 is easily the most common G12H model from the 70’s. It was the stock speaker with many UK brands in the 1970’s, such as Orange and Carlsbro, with Marshall being the notable exception.
Celestion G12H Creamback T1217 30WATT 16OHm 75HZ Date 1978