Is the red data plate on a 850 Interpol under the seat?

It was on my Mk2A (bought from Avon&Somerset in 1979).

Both under seat on account of the fairing support bracketry around the headstock.

J

Mine is on the headstock (Mk3). Where do you have the holes for the plate on your frame?

Regards, Al.

Look for the four holes where it was fixed to the frame.   J

Here's a picture of mine:

My frame also has the VIN plate fixing holes in the usual place on the headstock. It is likely that the holes in the headstock were put there by the frame manufacturer. The under seat plate will have been put there during assembly at the Norton factory and, as you see, is not square to the frame tube - so someone with a black&decker.

As for why yours doesn't have a plate: some Commandos didn't and the V5 shows the frame number stamped into the RHS of the headstock; or yours is a replacement  frame, a lot can happen in 50 years.

Not familiar with that fairing, although that doesn't mean it's not right. Mine (1974 Mk2A) looked like this: https://classic-motorbikes.net/wp-content/uploads/2015/10/10559.jpg (with brake caliper on front left).

Good thing about ex-police bikes was they were original and complete, bad thing was they were knackered from high mileage and plod's riding style.

My 74 Mk11a Interpol has the front brake caliper on the drive side. I guess a reputation for police bikes being worn out is dated now? The crank on mine was interesting as it had no rotor keyway (one was impossibly situated in the thread on the end of the crankshaft?!) but the flywheel had been drilled, the odd cylinder stud hellicoiled and that brake disk drilled and skimmed, so properly engineered maintenance. I suspect it's 55k miles is about right and I have replaced bearings and seals etc etc as it's 50 years old, so rarity is now an asset in my opinion. Incidentally does anyone know the thread for the petrol tank radio fixings?

My mk3 ex Ipol #334xxx was factory accepted in July 1975 & despatched March 1976 - it had the VIN under the seat but the 4 holes on the headstock were there also & I have now put it there. It came from Lancashire police and was bought by the guy's father from whom I purchased it.

They were both on it many years ago & were stopped by the police. Why have you stopped us officer? Ans: I used to ride this bike & it was a bit of a pig. It threw a rod so obviously needed new cases - there is currently no engine number on the case in the usual place. It also caught fire with all that wiring!

When I arrived at the Solstice rally last Friday, I was approached by a gentleman (I think it was Arthur from Preston) who enquired if this was an ex-police bike. He recognised the number plate as they bought bikes in batches & he used to work in the Lancashire police garage. After Nortons finished, they stuck with BMWs.

1/4" UNF.

I may try a Jack Russell sized tank bag affair..