Hello Buz2368 and welcome to this great Heartland Owners Forum.
I think your best bet would be to contact Heartland Parts. They should be able to set you up.
574-262-8030
And congrats on the new to you RW.
Oh, if your rig came with TowMax tires I would recommend replacing all of them.
No matter what brand is on there they are nearing the end of their useful life.
Peace
Dave