Hi schnikes55,
I’m not sure which city you are closest to but if you are in the Allentown-Bethlehem area then the closest factory direct manufacturers are in Post #6 here.
There is also a larger list of manufacturers in an area centered around Trenton, NJ in post #4 here.
There are some very good choices in these outlets depending of course on which are close enough to warrant a visit and the type of mattress you are looking for.
Good luck in your warranty claim. Normally what happens with a warranty claim is that an “inspector” will come to measure the depth of the impressions (with you off the mattress) and if it is more than the warranty exclusion and if there are no other issues that would void the warranty then a claim will proceed. Spring Air went bankrupt in 2009 however so warranty claims are “problematic” to say the least.
Hope this helps
Phoenix