Not all hornblock bearings are alike.
AGW and LRM bearings are similar, but AGW has the sliding groove running down the centre of the sliding surface, whereas LRM is biased to one side.
I've used AGW bearings in an experimental LMS Duchess chassis, but I didn't use the 0.45mm guide wire supplied as this makes the bearings too loose in the guides. I found 0.6 or 0.7mm wire to give much better sliding characteristics.
High Level bearings are smaller, as are the guides.
Then there's the rectangular Brassmasters/Comet bearings which are designed to slot into the frames directly without needing separate guides.