Query: Dates of old square dance records

Does anyone know of a guide for determining the dates of issue of old square(/contra/folk) dance records? Most such records have no date printed on the label. And even where publication dates are given on the label or packaging, they typically won't be in included in listings of the records in printed or online catalogs. It has occurred to me that one might go through the archives of _Sets in Order_ and/or _American Squares_ http://newsquaremusic.com/ASDindexUNH.html http://newsquaremusic.com/sioindex.html (many thanks, btw, to Gardner Patton for digitizing these, to the publishers for granting permission, and to the University of Denver and the University of New Hampshire for hosting), looking at, say, the last issue published in each year and noting the catalog numbers of records reviewed or advertised, especially those indicated as being new. This information might provide a rough timeline from which one could guess the approximate issue dates of other records made by the same companies. It has also occurred to me that someone might already have compiled such a timeline, whether based on magazine ads or oh other sources of information. *** Do any of you know of such a thing? I am of course aware that various complications might come up in dating SD record: A particular company may have used more than one series of catalog numbers. A recording originally issued pn a 78 RPM disc may later have been reissued as a 45 or as one track on a 33 RPM LP. An instrumental recording might later be used as music for called recording. Record companies might get bough out and some of their might be reissues with new numbers. Some catalogs list records with distributor stock numbers that may have no obvious relation to the record producers' catalog numbers. I seem to recall reading about one label (Folk Dancer?) that issued records for years with the same copyright date on all the labels. Maybe there are other significant issues I've overlooked. I also know that for any particular record there are various web searches I might try in order to get a clue about its date. But thos could get rather tedious if one were trying to find approximate dates for dozens or hundreds of records. Thanks in advance to anyone who can point me useful resources/ --Jim