Greetings,
I have a catalog from the "Sole U.K. Motobecane Importers and Distributors" (Motor Imports Company Limited, Croydon, CR9 4QX, England).
The catalog is undated, but it does list this model (among 6 others), shows the bike in a black and white photo, and briefly describes some of the features.
Following is all the info presented for this model:
--------------------- FRAME: 3 Reynolds 531 tubes -- front and rear forged Huret tips -- Sizes 53.5 cm (21"), 56.5 cm (22.1/4"), 59 cm (23.1/4").
WHEELS: Record racing rims -- highly resistant spokes -- Wolber racing tubulars -- Normandy large flange front and rear hubs -- Normandy quick releases
TRANSMISSION: 10 speed -- front and rear Huret Challenger derailleurs - down-tube shifters -- Stronglight 49 chainwheel and crank set -- 14-17-19-2-26 teeth rear sprocket -- 42 x 52 teeth double chainwheel.
HANDLEBAR: Light alloy reinforced Pivo racing type -- light alloy Pivo BTR stem -- plastic end plugs and tape -- Lightrace head set.
BRAKES: side-pull Universal Super 68 -- Universal racing levers with rubber hand rests.
SADDLE: suede, Italia Grand Prix Professionel -- light alloy seat post.
PEDALS: Atom 440, light alloy
EQUIPMENT: toe-clips -- straps -- Zefal pump with instant adaptor and clip
DECORATION: chromed front fork tips.
COLOURS: silver blue. -----------------
Any odd spellings typed above are not errors; I reproduced the Franco-English exactly as it appeared, and the cataloque is marked on the back cover as printed in France, so...
An inserted price sheet (dated 23rd June 1975) lists this model as the importer's most expensive [of the 6 offered in the UK]: --------------------- Basic Price £106.48 V.A.T. £8.52 R.S.P. including V.A.T. £115.00 ----------------------
In the photo, there is "MOTOBECANE" on block lettering on the sides of the seat tube and the down tube. Also, the bands above and below on the seat tube appear just as in your photos of the actual bike. And, even the Reynolds sticker is placed high on the down tube, as on your bike. Berto's book "The Dancing Chain" lists the Huret Challenger derailleur as 1974 vintage, too.
So, even though the paint scheme looks different than what we've seen in the US during the mid 70s, this looks to be completely legit for around that date.
If the wheels are original, you might want to check for a date. Those look like Normandy "Sport" hubs, and they often were stamped with a date visible right on the outside of the hub "barrel".
Hope this is some help.
Bob Hanson, Albuquerque, New Mexico, USA