Many many variations of those engines, and no, there are no actual parts on the engine itself specific to any other manufacturer. With the CPL number off the engine tag Cummins can tell exactly what configuration that engine is and exactly how it is specced and setup. Unless of course it is a transplant. I own several of them and work on many and have never once ever needed a parts book. The BC I engine in my versy 875 is no different in basic engine configuration than what the BC I is in my one truck, except for things like the fuel pump and fan mount for example. Only place you start pulling big differences is when you get into marine apps. I'm wondering if part of your trouble is the typical one many of us run into, that being the engine is older than the person looking it up and they haven't got a clue what you are talking about.
You will need the engine serial number as well as the CPL, but this site with Cummins maybe able to help you out. Link posted below. You will need to register, it is free, however I don't believe you can get far by not registering. You can register up to five engines. If in the event your engine tag is missing, at the top left corner of the block, just below the head at the rear corner, the engine serial number is stamped into the block. Again, this only helps if the block is original.
The gasket you mention is simply the one for the pump drive blank cover, nothing special with that for industrial apps, be exactly the same one used when the hole is blanked off on the front cover, if you can't get one, simply make one.
Suction line varies depending upon type of oil pan, stamped steel vs aluminium, forward vs rear sump, again, not much special with any of it. If it is a hose, simply make a new one, the hose ends are reusable and the hose is simple single steel braid fabric coated.