Proposition 1: An educated guess is better than no information at all.
Proposition 2: An educated guess is only as good as the education that goes into it. Interpolation works better with larger samples than with smaller ones. It works better with years of release (usually) than it does with months because of the erratic nature of nearly every label's release schedule. The process will be undermined if any portion of the sampling consists of wild-ass guesses (i.e. Un- or barely-educated), which produces outliers like 1 to 6-year misses.
Proposition 3: Better control of data starts with better awareness of where the data comes from. Right now, anybody can fill in any missing date. You don't ask, and they don't have to tell, how they arrived at it. The same could be said about any field in the entry when someone is providing a new item. I'm all for transparency. A world of evils would be greatly alleviated if people had to own up to their sources and their techniques, or better yet, actually have a source or a technique.
Proposition 4: Easy participation encourages participation. More difficult participation discourages it. Where to draw the line....? Good issues for a moderator to address.
I won't be opening any forums, but let me know if you do.
Steven C Barr in "The Almost Complete78rpm Dating Guide II" page 102 (available here) suggests June 1950 for C240. This makes me wonder how valid/accurate the idea of interpolation using supplied dates in our listings can be, and if we should accept them.
I recently updated many HMV UK dates (1925 - 1943) in our listings to month of issue using HMV supplied release dates, and found errors of up to 6 years, with many being one or two years out. Based on that exercise I'd be very cautious of using interpolation rather than documentary evidence. Perhaps a topic for the forums?
Based on information submitted with surrounding numbers, I would have guessed the year of release to be 1949, but I have learned that this disc was not recorded until February of 1950. (Jazz Discographies Unlimited, Glenn Miller Alumni Vol. 1). Since it couldn't have been released any earlier than that and the likelihood that it was released any later than 1950 is slim, that's what I'm left with.