Thanks again all for your tips and suggestions.
08.58 Chur-St Moritz was cancelled at Filisur. Passengers on bus forward but then train went empty forward about 15 mins later. Loco 643
The helpful ladies at Filisur provided me with a loco digest which showed 2 out of the 4 locomotives I am looking for at work
09.58 Chur-St Moritz ran as booked with loco 649 which I took to Sameden.
12.02 Pontresina-Scuol was loco 618. This was taken to La Punt Chamues CH.
11.32 Scuol-Pontersina was loco 614 one on my list which I travelled all the way to Pontersina and back to Susch (13.02 from Pontresina)
13.20 Landquart-St Moritz was another loco on the list - 620. This route was suffering delays of around 7 minutes due to the Scuol-Pontresina services having an additional reversal in the tunnel.
16.45 St Moritz-Landquart was 703 (The loco digest had this down as 702) As we departed St Moritz 705 had arrived but can not see what working this would have been.
IC936 18.39 Chur-Zúrich was showing Ausful at Landquart. I arrived Chur at 19.05 as 11244 was departing empty towards Landquart.
An interesting day with glorious weather.