Yes, you can absolutely use the Stromberg Carlson Extend-A-Shower Shower Curtain Rod for RVs # EXT-3542S to replace the shower doors on your 2021 Heartland RV North Travel Trailer.
This is going to work with 35" - 42" wide RV showers and will accept any standard curtain which you can get from a local home improvement or department store. view full answer...
Looks like you have the Pendant Light part # 277-000422 and are trying to replace the shade with the seeded glass shade part # 277-000431. I spoke with my contact at Gustafson about the install process for the shade and they sent me:
"He has to loosen the wiring from the bottom of the base and feed the socket through the glass. That is how the glass is installed. It is not meant for the end user to replace, but many have done so. Usually has to be done by a service agent." view full answer...