If those chips under the clear adhesive / glob-top were silicon die, that was wire-bonded to the pads rather than soldered (Even zooming into image, it's not detailed enough to tell), then the die is usually glued down underneath it. So that adhesive (or solder if soldered) must have failed as well.
They probably haven't made 2114 SRAM IC's in the last 30 years, so all are going to be similar age. But after buying quite a few used 'pulls from sockets' ones, several 10's of these have passed OK on the Arduino 2114 tester board (Which I presume can run these at close to their max. speed). So I must have been lucky to not to have any failures, but I don't encounter these as much as DRAM's - of which I've had lots of 4116 & TMS4532 (already half-failed 4164) failures (although rarely 4816 & 4164's)
Yes, the cost of that book is rather high - even for a used one.
Although its much cheaper (especially for used ones) in the USA, even with delivery to UK selected:
https://www.amazon.com/8080A-8085-As.../dp/0931988101
And could pobably get a whole batch printed for their new cost, with a free PDF of it here:
https://www.pdfdrive.com/8080a8085-a...e34426939.html