the Marlow Branch runs between Maidenhead & Marlow with stations on the line the trains calls at Furze Platt, Cookham, Bourne End & Marlow the line is run by class 165 and the line is 7 miles long
If you have the required DLC, which isn’t a lot, the freeware Wycombe Joint Line route has the Marlow branch which, as it is set in the fifties, also continues from Bourne End to High Wycombe. Available here: https://www.steamsoundssupreme.com/page_fwrp01.html
