Re the 27th Dec:
The 13:00 Penzance to Plymouth was a coach at least as far as Truro. Also some services on the St Ives branch were provided by a rail replacement bus due to train crew shortages. Felt a bit sorry for rail passengers at St Ives who were going to Carbis Bay who were told that the replacement bus was going non-stop to St Erth despite the fact it had spare seats and had to pass through Carbis Bay anyway. As First operate local bus services in the area passengers for intermediate St Ives branch stations were advised, by a poster, that their rail tickets were valid on local bus services.
Incidentally noticed signs at St Erth saying that, due to the frequency of branch services and the short turnaround time at St Ives and St Erth, branch line services will not wait for (late) mainline services.