Had a look at the diagrams
SO
There are 5-7 spare 318/320 units at Yoker on a Saturday, 2 off whicj should operate Yoker to Shields but rarely run in the morning
There is one spare unit at Motherwell TMD on a Saturday, so if the empty Glasgow Central to Motherwell Weighs CHS FO ran to TMD then the spare unit could go to Glasgow Central high level on Sat am, and could return on the 2320 Glasgow to Newton on Sat evening.
We know one diagram is already covered.
The 6 car due to run Shields to Yoker Sat am could be held for 380/385 cover on Saturday…. With the 2 units that are booked to run Yoker CS to Shields operating what the 2 units arriving at Yoker would operate.
Sunday there are enough 380 units spare to operate East Kilbride services or the soare 385 units could operate Inverclyde to release 380 units or 385 operate Lanark to release 318/320 to release 380