You may have some luck trying the RV surplus stores around Goshen area.
There are 3 that I try to get to when up there:
Bontrager's
Rainbow Variety
Johnsons RV Surplus
Bontrager's & Johnson's are right across the state line in Michigan on RT 12. Rainbow is down the road from the Elkhart County Fairgrounds on County Rd 34 in Goshen.