50's Silver tank paint 500T

Hello,

I'm about to paint my 500T fuel tank. I would like to know if anybody has a modern paint code for a close match.

I have a code...

Silver Birch 3404/M

I have taken this code to two auto paint mixers /suppliers neither recognise this code. They also told me that many manufacturers have the colour 'Silver Birch'

I would imagine that most if not all silver tanks in the 50's were painted in the same silver.

Was it a metallic or a flat colour, the latter I would imagine. Can anyone give me some guidance? Thanks...

Regards
Garry