Tim,
You are right and I don't have a good handle on my childhood. The first 45 was not issued until 1949 by RCA and was a direct response to CBS putting out the 33 1/3 in 1948. The confusion arose from the old RCA 45s I have from the early 50's or whenever. I have some 47-xxx, 48-xxx, 49-xxx, and 52-xxx numbers. It was all too easy to jump to the conclusion that those numbers represented years without checking the facts and they were close enough to be plausible. I haven't found a catalog of RCA releases from that time period to find out exactly when they were issued. Record makers (45 & LP) were notoriously poor in putting issue dates on their products.
rich r