Apropos the Clymer Loop line, here's almost an hour of video from the Youtube of 4 days spent chasing a train from Clearfield to the loadout above Clymer, then back and out to Ebensburg (ish) - circa 2010. (Corman regularly is not in a hurry)
As it happens, Atlas ran 7697 and 7709 in HO (but in the silver strip scheme variant).
I give this train bonus points for the street running in Clearfield and the ex-Con GP38's with their old 3 chime airhorns. The ex-D&RGW tunnel motor doesn't sound too bad, either.