Okay... not the 07 in this case.
The 07 is listed as a clock divider; generates horizontal and vertical timing pulses divided down from master clock (Sync Generator)
I checked the 6MHZ test point on the scope, it's the same freq as a working video board, but a lower (about half) amplitude. Looking at the bottom side of the board by the clock; the PCB under the 74S163 is browned from heat. I can't imagine a 74 series chip being able to run at the heat required to do that and still come out in good shape over a long period of time. Max temp for these is 70ºC (according to the datasheet), that's about 158ºF. I can't see that scorching a PCB. So... she's been running a little hot. But maybe it's still working as intended?
As it's a counter, I have no idea how to test it in circuit.
Anyways... going to keep tinkering till it's either fixed or broken beyond repair. ;P