I took a trip out to Forteviot to see the mud oil tanks but they failed to show during the limited time I had. 170402 passes by with 1A73 1542 Glasgow Queen Street to Aberdeen.
Another working off Glasgow's Queen Street station is 1H15 1612 to Inverness with 170419 forming the train. The set passes over the low bridge carrying the line over the Water of May, a tributary of the River Earn.
The sun is right down the line and favours neither side at this point but the back cab is well lit.