has that back plate been cut afterwards or was it angled like that from factory ?
Welcome to the nightmare of Armourless carriers, iam trying to find someone who would be willing to measure up armour on their carrier plotting all the holes and visors so i can CAD them, once that is done the file can be emailed to anyone in your predicament to get the sheet metal cut on a water jet. the next problem would be getting toolage to rivet them on as they should be.
i have heard you can get road wheels re done (here in the UK) for circa £40 per wheel, this would include idlers or any wheel with a rubber band
person to speak with is Clive Hughes from
www.milweb.net (Hughs movie supplies) make sure you speak with Clive and Not Ian as its Clive that is well clued up on carriers and is a really nice bloke indeed !
good luck with your quest buddy
Richard