Theres something not right here that requires further investigation.
As posted above - Your M codes plate shows the following information :-
Model Type 2 (T2) mod. 234(0) :
- Kombi
- Sliding door left
- RHD
Chassis number 2332097956
Serial number 097 956
Model year 1973
Planned production date Thursday, 21 December 1972
Number for production planning (temporary serial number) 7361
Type of engine Type 1 (AD) - 1584cc, 37 kW (50 bhp DIN)
Type of transmission Manual 4-speed gearbox
Paint color *** Unknown ***
Interior color (door panels and seats) II - *** Unknown ***
Destination England, Ramsgate
Note.. this chassis number would tally with the body features you described since it would be a 73 model year.
The chassis number you have quoted "2312217667" is a chassis number for a 1971 model year vehicle and does not tally with the M plate of your vehicle.
Where did you get the chassis number from - was it from paperwork or log book or physically from the vehicle itself?
If your vehicle is a 1971 then the rear valence (the bit between the engine and the rear bumper) will be bolted in place, not welded. To the right of this panel, inside the engine compartment, you will find the chassis number stamped into the chassis member.
If your valence is welded in then the chassis number is on the left side close to where the foam seal meets the engine compartment - see here for pictures http://www.thesamba.com/vw/forum/viewtopic.php?p=3699084" onclick="window.open(this.href);return false;
Let me know what you find please