Nice I am a little earlier than you then (Modeling wise) being early 30's either way, the driver is about perfect for LMS period work.
as I say, add a fiber washer onto the axles one side of the chassis and that should kill most of the slop, a little is needed but not too much as you say. That lack of exactness and accuracy is why I am now working in EM. Track building as not that hard to do when you get into it, nor is re-gaugeing (EM you can simple spread the wheels on most stanadard wagon axles) and I have never bothered with compensation, just lay the track well and double and tripple check gauge and alinement and you cannot go far wrong, the visual difference on hand built points is staggering, as is loosing the Hornby/peco hinge on the switch rails and scale guard rails
you can get flexi track in EM now, and point kits, yes they take longer to build and are a little more expencive, but in the long run they look better and the visual difference for a steam loco is pronominal!
Just a few thoughts for you to chew over my friend!
Sea