Can you help identify the boards in these numbered pictures? Thanks in advance.

25 You will need to remove the Dallas real time clock chip as they contain a lithium battery. High telecom if you remove the bracket also, gold finger card with bracket otherwise.
21. Remove the heatsink. High telecom if you remove the bracket also, gold finger card with bracket otherwise.
20 At least low telecom, but need to see the other side
22, 23 backplane
24 High peripheral

Here's the backside of board 20. Is it telecom?

Yeah I'd go with low telecom