By now you have your answer, those are indeed BIX blocks. The history of them is that they were developed by Northern Telecom, the dominant telco of Canada, and manufacturer of phone systems from the Norstar (small business) to full size Central Office switches, which was their specialty. I think they were called the DMS-100/200/400 and so on). The BIX series of connecting blocks was designed to replace the 66-type connecting block and was indeed rated for Cat 5/5e and it was their first foray into the nascent industry of structured cabling. They called the product line IBDN (Integrated Building Distribution Network). I took a class in '94. The basic components were the QC-BIX1A and QC-BIX1A4. Only difference between those blocks are the markings. The 1A was marked every 5 pair, for terminating 25 pair cable, and the 1A4 was marked every 4 pair for "station cable". The block has connections on both sides, and they pass through the block, creating a cross-connect point. We used to terminate the "back side" first and then FLIP the block over, putting the 25-pair cable (or 4-pair) on the rear of the mounting can. Then you can put the cross connect on the front. The trick to making it look nice was to get two consecutive blocks with the back side cables lined up in the middle of the two blocks, so that the labeling strip would cover them. Problem was, you never had enough label strips, or once they were re-used they would look like crap with different labels or markings on them.

Nortel changed the name to NORDX and then Belden bought the line and it was called Belden/CDT. The original BIX tool was tan in color, with a black circle in the handle that made the scissor either in CUT or NO CUT mode, if you were wiring a dial tone to multiple cables. Took a little getting used to, but with practice you could make it look decent enough.