If it was registered as Valentino, there is an AKC registered B with that name. It was born 12-15-94 and is a male and is red & white. I do not know if this is the same dog though. Your Valentino could be registered under another registry like APRI, ACA, CKC, UABR, etc. According to the AKC it has only one littermate who was registered and that is Cambria's Tambour.
It is my understanding that someone in CA had used the kennel name of Cambria recently and is not the same breeder that used the original kennel name of Cambria in the 1950s, 60s and 70s. Someone on this forum who lives in CA can correct me if I am mistaken.
If the owner thinks this may be the sire of his dog, he can order a 5 generation online pedigree from AKC for $12.00. It would have the breeder of Valentino on it. It would not have who bred him and to what female and the offspring.
Does he have any other information about his dog? I presume he lost or misplaced the paperwork that came with his dog when he bought it at the petstore. How does he know the breeder is from MO? Does he have the breeder's name? If so, one could look it up in the USDA database, if the breeder is still breeding and selling to petstores and has a USDA license. The dealer/broker Hunte Corp. is based in MO but it buys pups from breeders from other states. I would guess the states could be MO, AR, OK, KS, IA, and NE. These are the big commercial dog breeding states but he could have come from another state besides these though.
I am not familiar with a B with the name of Valentino and I have seen a lot of commercial breeding dogs' pedigrees. Perhaps someone else in rescue is familiar with him.
Jennifer