Starting to think..
Firstly about what happens with relatively decent curves turning from a 2ft board onto a 1ft wide board.
Easily room for 4 tracks, 5 if necessary, with R3 as the minimum, With R4, four tracks would be tight but OK.
Broad possibilities with that.
A double track looped 8, with a bridge crossing in the board opposite the main station.
If the station is at bottom level and only one track climbs, the gradients are reasonable ~1:45.
If the station is at +1 inch so the lower line at the bridge can have dropped that, the gradients are nice.
At the station one double line goes into four platform faces (probably) while the rear one goes into four to provide two full-length storage loops.
(if they could be got to hold two trains each that would be a bonus)
These would be behind a retaining wall with townscape above.
An alternate would be to have a simpler double track oval (with extra platforms at station and a pair of storage loops elsewhere )
and the inner area as a single-track branch line, with a passing station on the opposite side of the layout
This could be configured as an oval, running through the main station, or it could run bay platform to bay platform at the main station, the two facing in opposite directions (separated by a station building would be nice...)
The thought here is that the passenger service survives because a couple of modest rail served industries also use the branch.
If they need each other's wagons it would solve the problem of where most of the specialised wagons go, to and from.
They should not too conveniently feed each other.