Hole in block below alternator adjuster?

[clabelle05]

I am trying to figure out what is suppose to go in the open hole below alternator adjuster at the front of the engine on a 1967 250 SL also what goes in the open hole in between the the two banjo bolts with the tube connecting them on the head. While we are at it, there is an open hole above the alternator bracket on the right side of engine. I looked at the picture with all  the holes that pass through the block however there is no picture with the accessories in place

[Benz Dr.]

I think some of those holes are for mounting an AC compressor bracket.

[clabelle05]

I would agree with you, however the picture that has been posted on here states that these are through holes and a possible area for oil to pass out of the engine. My car does not have AC and it does not have any boles in these holes. Should there be bolts?