Hi Dave,
A brief look at the pics tells me you should either replace the steel gears or spend some long, careful time with a file and emery cloth to dress and clean up the tooth pressure faces... They're chewing up the brass gear quite efficiently...
Mesh looks a little loose, it could be improved upon, but the machining marks on the steel gears are "quite bad" to put it gently....
My not even .0001c worth...
Cheers
Ed