Dear Piero,
If you think your mudguards are genuine, there never was swept-back pipes, rear-sets and a reverse g/b cam plate fitted to your bike. It was probably assembled or re-manufactured after termination of the cafe-racer production run early in 1967. As mentioned by Paul Morin, last cafe-racer styled G15CSR or M33CSR was S/N 120511. Does your serial number exceed this?
Numerous unsold G15 and possibly some M33 bikes made in late 1966 and early 1967 were put into storage at AMC (by then N-V Matchless Division), robbed of cycle parts which were used for spares, and later sold at discount prices using cycle and engine parts off later models. Thus, it's possible your M33CSR was made late in 1966, put into storage, "remanufactured" in the autumn of 1967 and subsequenly shipped to the Italian importer. The "remanufacture" may have included fitting mudguards off the contemporary G15CSR which by then had become a sports tourer. The parts used are not listed in the last spares book - I believe they are the same as the last G15CS, but not sure of this. I would be interested to have this confirmed.
The twin seat is another chapter. For bikes made and delivered in the 1967 manufacturing year, the seat fitted was to 1965 spec - 031528. Bikes made or remanufactured for the 1968 model year received a new seat off the G15CS which had chrome trim along the border, p/n 032271. Thus you will find 1967 G15CSR in sports-touring guise (no rear-sets and no swept-back headers) having alloy mudguards and the 031528 seat, concentric carbs and coil ignition, and a similar 1968 G15CSR having steel mudguards and the 032271 seat. The build book changed with each batch, it seems.
Maybe the batches were so small (50 to 200 bikes) that N-V considered it worthless to revise the spare parts book. This must have been the case for the model 33, of which few bikes seem to have been in storage, as I have never seen a 1968 model year 33 or 33CSR. Remember, at this time N-V was very focused on developing the Commando, the P11 series and the Y4 Stormer m-x bike. Apart from the small updates mentioned on re-manufactured bikes to clear stocks, the assembly line for the G15, 650SS and Atlas models came to an end during 2. Quarter 1968. However, the Dommie assembly line was later revitalised for the 650 Mercury model, an entry level model. Assembly of the Mercury started in October 1968 and lasted until February 1970.
Here is a restored sample of a G15CSR made in the spring of 1967 and probably sold as a 1968 model (which it is not). Please notice Concentric carbs and coil ignition.
One of the last G15CSR's (including "ape hanger" handlebar) coming off the assembly line in late spring / summer of 1967. This sample is claimed to be completely original, however 18" wheels are out of place for a '67 model:
https://www.pressreader.com/australia/old-bike-australasia/20160804/282660391785828
Here is an extract of Paul Morin's article on the Norton-Matchless Hybrids.
"The (
G15 and M33, my comment) C.S.R continued production through 1966 (when the 18" wheels were changed to 19", thus slightly increasing the gearing as both sizes used 3.50 rear tyres) until early 1967. The last 'café-racer' was 120511. After this the 33 C.S.R. was dropped and the Matchless lost its 'café-racer' status, (a sure indication that the Rocker period had passed) and coil/Concentric models with standard footrests and normal exhaust-pipes using Norton silencers converted the machine into a 'sports tourer' (approx. 50 produced). The 'café-racer' C.S.R. machines did not use Norton silencers because of clearance problems with the positioning of the rearset items. However an unusual final batch in mid-1967 was produced. The large petrol tank was replaced with a 2 gallon scrambles item but with chrome sides, and with high 'ape-hanger' handlebars the C.S.R. capitulated as an American styled 'street machine' (approx. 50 produced)."
Regards,
Knut
