Mine is stamped on the top of one of the front dumb irons.
https://farm2.staticflickr.com/1876/...acb30a37_c.jpgChassis number by Colin Radley, on Flickr
I did read that CKD assemblers (Regent Motors, Grenville Motors etc.) stamped the chassis numbers in different locations.
I met an elderly gent a few years back who worked at Regent Motors and the chassis came in a separate parts which they welded together to keep the costs down (and therefore the duty paid). This would probably mean that the chassis number wasn't on the chassis rail when delivered.
I have some number & letter stamps you can borrow [bigwhistle]
Colin

