From what i can tell from the engine number ( 6T 018114) its a pre unit. The number i found is stamped in not raised.
The frame number would have matched the engine number originally, so I doubt that the stamped number you found is the frame number? 6T 018114 would make the engine a 1958 model.
In order to upload a photo directly into your message it has to no more than 100KB file size, so it is generally necessary to reduce the picture quality as well as the actual size?
I find Photobucket works OK for me here.
Try copying the URL *IMG Code* line of the Photobucket photo, then paste it directly into your message, and do not paste the IMG Code into the Attach box.
Or if that still doesn't work, try pasting the photo's URL *Direct link* line into your message?
Remember to leave spaces between any message text and the URL line.
Alternatively you can always email the photos to Nigel (VintageBike)? He will insert them into your message for you?