Avon searider - valves vs year - a7 b7 c7

[rmark]

The serial plates on my searider are illegible and so I do not know the year.
I have tried searching what year avon changed from a7 to b7 valves etc. To get indication of year of manufacture , but to no avail.

Cam anyone shed some light on this subject or by process of elimination by posting the valve you have and year of manufacture.

A7 has 2 nubs on cover/ cap
B7 has 3 nubs on cover
C7 has lots (7 or 8) nubs on cover

Robin

[paul tilley]

may not be original valves

[office888]

Remove the sacrificial transom plate. Underneath the engine, there is a hidden HIN stamped in to the gelcoat.

[rmark]

Sacrificial transom plate. Is this the wood on exterior or aluminium on top. Either is quite a big undertaking I imagine?