Thanks for the vote of confidence, Bill, but I'm not even going to try to straighten out all the voice credits here (I'll save that for the book). However, I can tell you that the DUMBO storyteller LP was released in October 1957, and according to Leonard Maltin, Ed Brophy was still in perfetly good health to have done Timothy Mouse again at that time.
On the LADY/TRAMP LP, Dal McKennon was not only Tramp but virtually all the other male voices (except Billy Bletcher as Trusty). He was the beaver as well, not Howard Morris. In fact, Dal claims to be the beaver in the movie itself. The voice does sound more like him than Freberg, so who knows? There might have been some faulty credits floating around. As far as the songs on the LP, Teri York performed all the female solos except the Siamese Cat Song, which was Robie Lester harmonizing with herself.
Oh, and for the other question... the Ludwig/All About Recording clip originally came from the longer "Ludwig Von Drake" LP from 1961. It is hilarious, as Frees ad-libs much of his dialogue and really goes crazy with it. Rumor has it that there is a tape of his outtakes from that session circulating out there somewhere, but I haven't heard it.
This could go on forever... and in the book, it will!