Insofar as the No1, No4 and 5 handguards are concerned, a lot of the blame (if that's the right word) for the shortage might go to the target and civilian shooters in the past. Unlike the Armourers in the past, the civvy shooters didn't bother to repair a broken or cracked handguard whereas we did in the Army especially when there were 'dues-out'. They are a relatively easy fix too. Usually just a couple of good slip patches, leave them a bit proud internally for strength, glued in with hot animal glue or aero strength/approved adhesive and make good. Even the broken or cracked ears (No1) are a simple fix. Not that I have done many (but certainly 30 or so.....) but in NZand in the Ord tech. stores at Bandiana, they had a jig that was used for cutting and holding the handguard while being repaired.
Just repair what's there I say. I know the purists might not like it. But those that know do.......