Hey Mark thanks for all the info. What should the AIR COVER look like??? I would swear it's original

Is that one plastic?  I think that's what they went to...  it's "original", just off a later model.

Original 76 was silver painted magnesium. 

 

Yes mine is a very hard plastic

Found this picture/ad the other  day  

And Mikkola won the world championship that year. 

I was told the 1976-1/2 bike had changes made to copy the factory works bike Mikkola used to win.  I heard this from a factory Husqvarna Mechanic who came out to an area next to the 91 freeway near Corona my Dad would take me to ride sometimes.  He was there to support Goat Breker...  an older kid whose Dad brought him to the same place and ended up with factory Husqvarna support.  He was SO much faster than me! 

The Swedish mechanic still had some older parts in his van and made a few tweaks to my "outdated" bike...  This was probably in late 1977/early 1978 and the new bikes had about 4 more inches of suspension travel.  My bike was just as fast if not a little quicker in a drag race on the flat though.  The 1976-1/2 has a strong engine. 

 

I'm keeping my eye out for the metal magnesium air box cover .... I've seen several pictures with the hard plastic like mine BUT I'm now convinced the metal was original.

Here's a picture of my brand new ML-11578 frame bike in front of Malcolm Smith's shop in Riverside.



Plastic air filter cover was definitely later model...  as was "round" magneto cover.  (I've seen a few earlier bikes with the later "round" mag cover...  yours has the correct one)

Here's the other side

 

The airbox cover should be a silver painted magnesium. I do see it has a Bing carb on it, they work well but the slide in those carbs were a very soft material and wore out easily. Most people swapped for a Mikuni or as Mark T did I believe is a Lectron. Marks starts very easily and runs great. The Motoplat ignitions get weak over time but can be rebuilt or swap to a newer electronic ignition. The shocks are, well, not that good. Those are the things I know we're problem areas. I had a 360.

Your bike is in great condition. I liked the 76 as they were a great desert bike. The factory and non factory riders won lots of races on those bikes.