Try sending an email to theses guys. They might cut a 6x3 panel in half .
Note it is hot dipped so you will have to check that the roughest side is downwards outside the cage to stop the rabbits getting sore hocks & starting a bacterial infection that will wipe out all your rabbits if it's not spotted in time ..
When my does kindled , about 10 days after till they were nearly three weeks old I put straw down on the floor of the cages so that when the babies came out they didn't get their legs stuck in the holes of the mesh it's not such a problem 15 x 40 mm 12 gauge mesh but the 15 x 50 do tend to get clogged with fecal matter from the larger does more than the 3/4 mesh ones do .
!9 mm mesh is the better size ( 3/4 " ) compared to the 25 mm mesh
www.ultimate-one.co.uk/fencing-applications-agricultural-wire-fencing-c-90_135?osCsid=kdqhqca7ken1tgh1n611v59165At the time we ceased rabbit farming white flat plastic floors were starting to come on the market . The best we saw had pyramid shaped holes in them this was used with the widest opening downwards . There were no sharp edges fecal matter occasionally built up on the walking surface but because of the cone shaped holes it rarely caused a problem for the people we knew who used them .we got some from Spain but I think a company called EAUDYKE rabbits near Spalding lincs was selling them ( expensive)
Perhaps a Google search for perforated plastic pet floor panels sort of thing might show them in use /available in the UK if Eaudyke is no longer farming rabbits .
You might also try looking for stainless steel mesh for your floors if you cannot find it in mild steel . Due to stainless being softer than steel two transverse support ( 8 to 10 mm ) rods might be needed to support the mid part of the floor . This mesh is made by auto spot welding and some times has very sharpe spurs on it at the joints a fine warding file takes them off nicely but be prepared to spend an hour or more per panel filing them smooth . For our really small miniature dwarf rabbits ( years of selective breeding ) we used 10 mm mesh for the whole cage to keep vermin out as the mini mini rabbits were worth a lot of money .