Interesting indeed. I'm owner of a 74 MK2, purchased new, out of the box in July of 1977 and am the original owner. Quite a story about the purchase but I won't go into that here. I discovered just today, mine was assembled with the MK2A chain guard. The original had stress cracked and rusted on the forward top end and a new replacement was received today. Pairing up new to old, I spotted a big difference. The original has a long slot cut out in the direction from rear to front and when guard is installed, allows one access to view brake shoe wear through an inspection port located on the brake plate. The MK2 guard I received has no slot and would completely cover the inspection port. That is the only MK2A item I can find on the bike. Filter box is metal, battery box runs lengthwise and left side cover has no lower Duiz connector. I prefer the function and look of the original MK2A guard and am sending the one received back for exchange.
