165mm AVRE help needed please

[SG500]

Thanks Harry that's perfect much appreciated.
Dave.

 

[HarryG]

No Problem

 

[SG500]

Hi Dave
Is this the one you are after, there is also a Mk2, L1A2 & Practice, Paint schemes being different.
Harry

Does anyone know when the Mk1 was replaced with the Mk 2?

Dave.

 

[HarryG]

Hi Dave
I don't know exactly but my drill is stamped for 7 / 54 .
Harry

 

[SG500]

I'm in the middle of a l long term restoration of a 165mm AVRE.

Regarding the screw on case. There's a 35mm diameter....thing....that sits around where the primer protrudes into the case with the following markings on it. does anyone know what its for please?
TESTEDNo 414
BRITISH PRE-FOCUS

Thanks

 

[tankbarrell]

That looks like the rim from a pre focus headlight bulb. They fit into the back of a headlight unit and the flange locates the bulb in the correct position for focussing the beam, hence pre focus. The circular notch locates against an indent in the lamp socket. Could it have been used as a firing circuit tester?

 

[tankbarrell]