I think the B may be for Brendel Informatik in Cologne, Germany. A
couple of years ago a U.S. company called "B&P Graphics Inc."
advertised a CD-ROM of Brendel types, and I got a demo diskette from
them. The fonts on the diskette have copyright notices for "B & P
Graphics Ltd." A text file on the diskette lists the fonts in the
"SERIALS Typecollection", including a large number of weights of
Columbia.
The address on the diskette label is:
B&P Graphics, Inc.
512 W. Burlington Ave.
La Grange IL 60525
(708) 352-3800