[78-L] test pressing query

[Donna Halper]

This is not my area of expertise, so perhaps somebody on the list can 
advise.  A friend of mine found a big album of 78s at a flea market-- 
he didn't know what they were (I mean, he knew what 78s are, but as 
you will see, this confused us both) and was curious about several things.

First, the album contains about 18 records, all of which say "TEST 
PRESSING, Columbia Recording Corporation."  Some have greenish-blue 
labels, some have white labels.  None identifies the artists, but all 
say "Budapest" on the label.  A couple of the matrix numbers:  XLP 
8021-16, and the label reads "Beethoven Q'tet, Budapest." Another 
reads XLP 9774-!E, and another reads XLP 8020-16.  Some have the 
words "Op. 18" on them (I assume that's Opus).  Later in the 
collection of test pressings, it sames "Brahms" rather than Beethoven 
but still says "Budapest" and "q'tet" on all of them.

When might these have been recorded and by whom?  And typically, who 
would have received this heavy album of 18 test pressings-- 
reviewers?  Concert promoters?  I doubt they would have been sold to 
the general public with no name of the group, would they have?