Marshall Excelsior is made in the US. Everything.
Here is their camp and RV catalog.
https://www.marshallexcelsior.com/sites/default/files/2021%20MEC%20RV%20Catalog.pdfVery useful catalog with lots of information. For pigtails, you need to decide how long, braided metal jacket or not, and 1/4 pipe thread or 1/4 reverse flare.
Get the part numbers and go searching on Amazon or elsewhere and see what you find.
Charles
'03 Ram 2500 CTD, 5.9HO six speed, PacBrake Exh Brake, std cab, long bed, Leer top and 2008 Bigfoot 25B21RB.. previously (both gone) 2008 Thor/Dutchman Freedom Spirit 180 & 2007 Winnebago View 23H Motorhome.