Bultaco Matador? Sherpa? CC? Year?

I received this bike and another (see my other auction) in a trade. I really don't know the model or year. Engine number is M-405241d, nd the frame number is B-403599. It is a four-speed and shifts as it should. The engine kicks over and feels like it has good compression, ut does not run. Shift is on the right, ear brake is on the left. Has IRZ carburetor with pump primer and it's 24-FC. AKRONT shouldered rims that are in very good condition. The head has two broken fins. Side cover has crack from shift leaver contact shown in photo. The seat camewith bike, ut not sure if it's correct. If anybody has more info on this bike, 'd appreciate the information. Do not have title, ill come with bill of sale.

On Nov-29-15 at 05:54:59 PST, eller added the following information:

You have a 250 Matador. The original 200 Matador used 4 as the first number, then when they made them 250cc, dded the 'D' on the end of the motor number. If you look at a model sheet, t will say the 250 Matador should start with the number 16, ll these years I've never seen a model 16, ll of them were model 4's with the 'D' on the end denoting 250cc, ncluding the one I'm looking at in my shop. The other guy isn't wrong, he very first Sherpa 'N''s used 4 as the first number, hen morphed into the 200 Matador that used the same number. Good Luck! Thanks for the info!