123/126 Transmission same or not?
 

I was sold a 126 trans to go in my 85 300td 123 and told it would go writ in .I think my leg was pulled real hard .
It looks very much the same but where you plug in the electrical/nutrel reverse light switcth is round on the 126 and gos behind the gear selecter and on the 123 its rectangel and gos in front of it. he told me i was stupid and didnt know what i was doing. I was told it came out of a 123 body typ car but he wont teme if the eng and trans were switched or not .Anyways i was just wondering if there is a way to change this or if maybe seeing is beleving it dos not look like it can work to me but who knows . Any sugestions ? thanks
ROB

Was just told it came out of the same year car it still dosent make sence to me. any help?