Thanks 18 Bravo. Shows how much I know, I had assumed that the wheel was some type of Soviet tank spare/replacement. Guess I'll have to move it to the front and add a second one.....assuming it would even be correct on an Mk. 1. of this time frame.
I'll see what I can do about adding the lightening wholes to the idlers. Thanks for pointing that out, I missed that detail in the walk around photos I looked at.
Here is where I got the inspiration for the Mk. 1 with chains circa 1982 Lebanon.
http://shaon.livejournal.com/70769.html You can also see them on the lead tank in the photo with the column of Merkavas
http://lebanon82.tripod.com/idf.htm It's hard to see, but there are bigger copies of that photo out there.
Thanks again.