Ok, I already figured out how to remove the cover. The fitting kit it came with is this one: Vintage Bike Bicycle Chain Guard Gard Fitting Kit Bolt Brakcet Raleigh BSA | eBay
The rear fixing bracket seems obviously designed to tighten the chaincase to the seat stay. One bolt does this job, and I presume the other bolt the kit comes with should tighten the case near the right crank. However, I have noticed my roadster does NOT have a threaded boss behind the right crank (Raleighs DID have this threaded boss for the chaincases, right?), so I have no idea how I will tighten the case near the right crank. Any suggestions on what mounts to use for this will be greatly appreciated. I am hoping it won't be necesary to drill a hole in my bike right behind the right crank!