I hadn't realised that headrests, as Triumph rather optimistically called them, were fitted that early though? Unless the car was sat in by someone weighing as much as I do, then the original seats would soon have lost their will to live.
the northwest group are quite a distance from you but still the nearest to you ,we meet the 1st monday in the mon th at the ring o bells pub in daresbury cheshire, eric noble runs the north west group and we have a good gathering at shows we go to houghton towers show which isnt far from you quite a few are in cheshire , woodvale at southport ,there is a member who as a L reg 1850 in honeysuckle and we have a 1974 1850 auto if you would like any more info give me a shout