Yes, I used Oilite bushes in my pedal box on the hatch. There is a standard size that fits based on the inner (shaft) and outer (pedal) diameters, but does need the top flange (or side flange, when it's fitted into a pedal box with a horizontal shaft) thinning out a bit. I removed most of the material from the brake pedal as that's under a bit less strain than the clutch pedal, though there wasn't much needed. Just enough to get a snug fit, virtually no sideways motion but loose enough to work properly.
When I bought them, I made up the order to get a better price by buying some smaller ones to adapt for the handbrake cable linkage, which also fit on the ZF clutch cable linkage. Had to decrease the outer diameter in those a little.
Pedal bushes are available from Vauxhall Green Parts and Magardsport, as far as I know, and maybe others. I think these are all the white ones. If I recall correctly, that's what I have in the Firenza without any serious issues, though it doesn't do a lot of mileage.
ETA - I'm talking about HC, I don't know if HB is any different.