I never heard that one on the barrel but the later kits addressed the track/sprocket problem.
Daryl Turner makes a sleeve to fix the barrel situation. It's about 5 or 6 bucks and glues inside the mantlet. I do believe the SCHUMO resin mantlets do not need it.
The space is pretty plentiful but it does have a huge speaker, so replacing it with a smaller unit would free up more room.
Jeff