Commando frame

72 frames did not have a frame number stamped directly onto the frame by the factory. The red plate on the headstock was stamped with the engine number and build date, if this is missing then you cannot trace the build date unless you know the engine number. Down on one of the gusset plates there will be a month/year code but this was a frame makers stamp, a clue but not a way to recover an identity.

If you have the old engine number than you can ask for build date from the Twins dating officer.

A number of frames around 1971/72 seem to have had incomplete or omitted dates. It's not clear either if the date was a build date or when the frame left the frame shop. It certainly wasn't a despatch date.

The Club should be able to confirm from the frame number.

I have a bike within 100# of your VIN/serial. It is a 1971. You should be able to see the reynolds build stamped date( if there)  which precedes the feb 71 date.

Nov and Dec 71 started 200000 combat series, so it is not a 72

The licensing authorities are only interested in the date of first registration.  In pre-emissions-norm days, it didn't matter if they had been made a week or a year before if they were declared 'new' by the manufacturer at the time of registration.

My 200500-ish 750 which would have been a late '71 build wasn't registered until August 1972 so was on an 'L' suffix rather than 'K' and my April '75 Mk3 850 wasn't registered until March 1976 so had a 'P' instead of an 'N'...sometimes it was just the case that a bike was an unpopular colour or trim type and sat in the showroom.

The important thing to bear in mind is that in terms of ordering spare parts, you have a 1971 model-year machine.