Wayte Raymond Unique Coin Holder board 339 for 1878 proof set

What's rarer than an 1878 proof set? Maybe the holder for it...
My latest acquisition.
The non-gold 1878 proof set included 1¢ 3¢ 5¢ 10¢ 20¢ 25¢ 50¢ Trade dollar Silver Dollar. It was the last year of the 20¢ denomination and the first for the Morgan dollar.
David Lange had not confirmed this type in his book: "The National Coin Album & Related Products of Beistle, Raymond & Meghrig (Coin Collecting Albums: A Complete History & Catalog Volume One)". They were not as popular as the album pages and only produced for a short time in the 1930's. These were originally designed to fit in a file box, but looks like a couple holes were drilled later.
Based on the pencil marks, it looks like it had been used for an 1880 proof set, then corrected by pen to 1881 (by a blackguard!) with helpful "Proof" under all but one opening (the 25¢) . I assume the taped label is an inventory - perhaps the ΦΦ a code. There is also a faint mark that looks like $150.
There is also some discussion of the Unique Coin Holders in this thread: https://forums.collectors.com/discussion/comment/13524989#Comment_13524989
Comments
That's pretty neat !
1881?
Cool, those are hard to find.
Mr_Spud
Congrats
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