Completely Worn Out CSB

[banditos]

1990 325i 230k miles.

Bought this car after it had been sitting for a while, drove it 10 hours home to Los Angeles from Oregon. Developed a loud rattling noise from the trans tunnel, suspected worn CSB.

Check out the attached image. Rubber is completely gone, driveshaft is moving freely in every direction. I laughed for like 10 mins when I saw it, because like a dumbass I had been driving with that CSB and the rattle for a solid 4 days!

Another interesting question, there was already a chalk mark connecting front and rear driveshaft peices, but the marks were not aligned.
Should I
a) make a new mark and align the driveshaft the way it is right now?
b) align the driveshaft using previously made mark
c) buy a new driveshaft, because obviously the splines have slipped and the thing is probably wrecked.

I can rotate the driveshaft just fine and there isn't even much play. Would rather not have to do option c :(

[RaidoM]

I don't really think that splines have slipped. Otherwise you would feel the clunk when you rotate the DS. Probably previous owner or somebody has replaced the CSB at some point, put the driveshaft together without watching those factory dots which has caused vibration and wrecked the new CSB.
I kind of had the same thing when i changed my DS. Old CSB was worn and DS was put together wrong (dots didn't line up). Installed the new CSB and lined up both sides as was shown in Bentley manual:
So far so good.