Wow!  This is the first 2519B shift register from Signetics I've ever seen on ebay (2 available) $110 And all of us who have had to shop around know that they are very hard to find!
Date code 1974.  (I found 11 in Germany and had to purchase the whole tube!)

By the way - the seller is the same guy I purchased my Datanetics keyboard  from years ago (serial number 10, stamped May 1976)   ( A few years ago, Mike Willegal cloned my keyboard I don't know if Mike has any kits left - from what I recall he had a relatively small production run)  Anyway, the seller generally has pretty fair prices - but he knows this chip is rare.

This one looks to be plastic, I believe mine are ceramic, I'd have to double check.

And there's another one on ebay here  (plastic) - 3 available, $120 each