It has been a while since I posted.
(I was trying to post photos but seemed to get an error

I own an early 70s OR120 and 4x12 cabinet which I understand from my original posts (2 years ago) may be an OM cab from late 60's early 70s.
To be sure about this it would be helpful if anyone out there had some pictures of the rear screw fixings compared to the later Orange cabs, as I think they were different.
OM cabs were 5 fixings per side compared to 4 fixings per side?
I understand the other major difference is the depth of the cab, OM being around 30 cms compared to 38 cms??
Moving onto the amp, my head has 4 visible pins fixing the chassis to the box, and many OR120's I see don't have these visible.
When did the design change and which one came first??
thanks for listening
GaryB