1/8″ axles will fit the chassis if the Hornby brass bearings are dispensed with.
This means the axles run in the mazak chassis.
Not good engineering but many old models run like this and survive.
But am hedging my bets by acquiring a Branchlines chassis kit.
This has a possible advantage over the Hornby chassis in that it can be sprung or compensated.
The Hornby chassis is rigid (OK, almost rigid!).
An issue will be loading up a new chassis with lead weights!
A project for later methinks.