M-101 changes

[gwalker]

I am familiar with the M-101 but what were the changes on the A1 an A2 versions an when did each get introduced?

 

[acetomatoco]

one of the last changes was to the surge brakes and CUCV wheels and tires on new axle set up... One of the first changes was to put a kit on to have two service tail lights and brake lights with a separate BO stop light...Chassis was the M116...family

 

[gwalker]

So likely the cucv unit was the A2, but what was the A1? I imagine dual lights came along same as all other MV's but I dont think that constituted an A1 model did it?