1977 240d with older engine? need help

[resago2000]

I have a 1977 240d with an automatic that was given to me.
I've replaced the injectors with some good ones from mercedes source.
runs well. average blowby.
when I can post up some pics, ignore the intake, the correct one was long gone.
the ac idle pulley was missing, so I bought one with the bolt, but I dont see where to put it.
I think it has an older engine, 76 or 75.
it has a york type ac compressor mounted high left.


probably needs a valve adjustment and oil change.


I need to figure out where to install the idler pulley
can someone post pics of the location or diagram?
is there a swivle bracket that i am missing?