You can cut out the HL intake top by removing the intake, then cut the two short sides with a razor saw, and then the remaining long side scribe in a couple of times with your hobby knife. Flex it and it will snap off at the scribe lines. Clean up the edges with a file. Cut a piece of sheet styrene to make the vertical wall under the intake screens. Use fine screen (dollar store tea strainer) and strips of sheet styrene with CA to make the intake cover. I'd use a bit finer strips and some bolt heads on my next effort. Always fun to keep improving once you've discovered you can actually do it. Check out the Sherman rear deck work by the DAK guys, sheet styrene galor and it's amazing.

Mike.