Question on oil filter housing

[asshanson]

I called in about this earlier today, I have a question about these front facing oil filter housings. Everywhere I look they say the part number is MD122260 but the guy on the phone couldn't find it, a pic is attached.

On the bottom center there is a port for the stock oil pressure sending unit, 1/8" bsp threads I believe. On the very right there is a bolt head, probably 17mm I think. Is that also an oil source, do you have any detailed info about these filter housings? I can't find any info about the bolt on the right.

I'm not sure how much info you can see about these on the computers or whatever, just thought I'd give it a shot. If anyone else knows more about these please feel free to reply.

Thanks,
Andrew