First time I've seen inside a 169. Not exactly impressive, although it does appear to be a lower-end model based on the ICL7106. Which are still available in 40-pin DIP, BTW.
Also, I'm relatively sure the meter comes apart by pulling up the top half of the case, leaving the front panel and circuit board in the bottom half.
A couple years ago I acquired a Keithley 197A, and the inside looks like a work of art to me. Probably an unfair comparison, in their day I'm sure there was quite a price differential.