typically it called a "gun hose" or "gun harness hose" or "harness hose" or even "harness assembly" and it usually comes as a complete unit. I don't believe the fitting end itself is just available for purchase, as even the service manual simply has it listed as an assy. (also stupid expensive)
the hose itself is called "stripwound interlocked metal hose" and is typically stainless steel.
i have in the past have had a company in town make up a hydraulic hose for me with a crimped SAE fitting on each end that i could fit a nut onto to keep it captive. it's wasn't high pressure hose, so it was fairly flexible.
if you aren't worried about theft or intentional damage, I would look at maybe just using a silicone or rubber hose. it'll feel much nicer. and can be terminated with some larger diameter tubing for some strain relief... and some well placed zip ties can hold it inside the gun/machine.
this could also be a project for a local makerspace. perhaps someone could make something that could be 3d printed... or an original style part be milled out of brass or aluminum.
sorry this post is not a "this part number is _____" post, but i hope it helps nonetheless.
