Help Identifying Auction Firms

I am breaking down a collection of U.S. stamps I recently purchased. The previous owner was diligent to make detailed notes behind each stamp mount about the date, cost and firm purchased from for each stamp in the album.
The firm names are abbreviated and was wondering if anyone here may have any insight as to the full name of some of the companies/dealers.

The abbreviations are as follows:
-- GV (I am certain this is Golden Valley Stamp Company)
-- AF
-- E. Mead or East Mead
-- RCS

Thanks much!
Harry

E. Mead would be East Meadow Stamp Co., a retailer which I bought from in the 1980's.

I am guessing that AF stands for Apfelbaum.

There's an outside chance that RCS is Regency Superior.

HarryG, It would be useful to know the approximate date ranges for these initials, since you have that data. We have no idea if you have a collection from the 1940s, 1980s or yesterday.

John - That's a great question!
I did a quick check of the dates and its quite interesting.
The dates range from 1984 thru 1987 and stop. Then pick up again in 2012 thru 2017.

Rogdcam - AF would make sense for Apfelbaum.

JLLebbert - I don't think RCS can be Regency. Too many stamps said to be from RCS are, well, "questionable"

Harry, no surprise about RCS not being Regency Superior. Only reason I considered it was the possibility that the c was being used to distinguish it from another auction house or dealer (e.g., Robert A. Siegel).

Added: Just had a thought. Since the previous user was fond of using abbreviations, is there any possibility that he secreted a "Legends" page somewhere? Unlikely, I know … or you would have already found it.

John L.

Interesting