This route has a few devlopers, you can find it here: https://alanthomsonsim.com/downloads/berks-and-hants-to-bristol-and-penzance/
(Fictional) Take a GWR 150/2 into service from Longrock depot, then work an early morning service from Penzance to St. Ives. You might be a bit delayed starting out due to a late running London service, do your best to keep to time but there may be some yellows in the way.
Difficulty: Medium
Duration: 40mins
Requirements:
AP class 150/2
DTG class 800 (plus Superalbs' GWR Reskin)
AP class 150/1 EP - recommended but not essential
Jamesivill's Mk3 sliding door patch and dependencies - recommended but not essential
You can find them here:
https://superalbs.weebly.com/train-sim-reskins.html
https://alanthomsonsim.com/downloads/mk3-sliding-door-pack/
https://www.armstrongpowerhouse.com/enhancements/multiple_unit/class_150-1_enhancement_pack
(Fictional). Take a local GWR service up the branch of the Takara line from Meldon to Exeter St. David's with a peak summertime service.
Difficulty: Medium
Requirements:
AP 150/1 EP
MJW 150/0 GWR reskin
DTG class 800 (plus Superalbs' GWR reskin)
You can find them here:
https://alanthomsonsim.com/?download=berks-and-hants-to-bristol-and-penzance
https://www.armstrongpowerhouse.com/class_150-1_enhancement_pack?search=150