First, an attempt at a link:
1967 review of Dirty Old Man LP on Columbia/Epic

And here's an excerpt. Delos Smith, critic for UPI.
Of all conceivable dubious enterprises, probably the most dubious is the one which has resulted in a recording called "Wolfgang Amadeus Mozart is a Dirty Old Man." Ugh! It is quite enough to turn a robust stomach....

....he was human, beyond the slightest doubt, as it witnessed by his fondness for what is now called "the bathroom joke." Nor has it ever been a secret that he, now and then, gave musical lines to scatological and other obscene verse.

All that has been accepted with a shrug -- and dismissed. But now, a big thing is being made of it -- a dirty record issued by Columbia under its Epic label (1366), one of the oldest and most respected names in the industry. On it are twelve obscene canons and songs by a composer celebrated for his aristocratic taste and sublime conceptions.

They survive as scraps and tatters, and to perform them it was necessary to fill in. Indeed, ten of the twelve accompaniments [note, not the vocal parts, the instrumental backing] were composed by Thomas Z. Shepard who was responsible for making the record, and who displayed monumental presumption by collaborating with Mozart even in obscenities. The responsible musicians are Norman Luboff, who conducted the chorus and a bevy of unknown soloists, and Igor Kipnis, the harpsichordist.

Anne Grossman translated the verses, and vividly so that none of the earthy expressions will be lost on English-language ears. Small boys toss four-letter words at one another, and laugh uproariously. But there's a market for such "humor" among adults. This record is for them.