Nick
I checked Andrea's thread and the plugs with the concentric circles (17 if you are interested) were replaced with the smooth topped type with the G model but you know, Paul's car being a kinda crossover model, early 74 production chassis number and all, he could have had the earlier type.
Have you no period close up photos of your rubbers ?
Correct early concentric ring type,
Regards
Mike
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73 RS (Sold)
67 S
Mint T (Sold)
996 Turbo (Sold)
73 2.4E (home after 25 years) and Sold again
73T targa (signal yellow project)
1953 Vauxhall Velox
914/6
1963 356B
https://www.mybespokeroom.com/