Sloper frame number

[Norton650]

Hi can anyone tell me where the frame number is located on a sloper frame it's the one with a I shape crossbar engine number is y9 any information would be grateful it's a restoration project that maybe coming up for sale

[JulianS]

Look at the seat tube end, either just in front, in the I section, facing to the left side or just to the rear of the seat tube on the forged member, also facing left.

The S31-9 frame would commence Y7.

[Norton650]

Thanks for the reply I'll have a look see if I can find it there