The list was alphabetical, and all over the USA - so here are some listed in the New England area-ish: I omitted a few with just berry bushes offered. But of course may have changed (if still existing..) Google may get you more about these, or if not try yellow pages for local ones.
Bigelow Nurseries Northboro Mass
Congdon and Weller Nursery Inc North Collins NY
Country Heritage Nursery Hartford Michigan * a lot of large nurseries listed in MI at the time
John Gordon Nursery North Tonawanda NY
Kelly Nurseries Dansville NY
Lennilia Farm Nursery Alburtis PA
Henry Leuthardt Nurseries, Long Island NY
Miller Nursery Canandaigua NY
New York State Fruit Testing, Geneva NY (this described as a nonprofit co-op nursery)
Pikes Peak Nurseries Penn Run PA
FW Schumacher Co. Sandwich MA (tree seed by the pound, I bought from them)
St. Lawrence Nurseries, Potsdam NY
Tripple Brook Farm Southampton MA
Wafler Nurseries Wolcott NY
Weston Nurseries Hopkinton MA
M Worley Nursery York Springs PA
My apple trees came from New Brunswick - Corn hill nursery and at the time offered Antanovka and Beautiful Arcade rootstocks as well as dwarf. Mine were on BA so one day my 'apple bushes' could even produce edible apples.
That is iff the snowshoe hare goes into deep decline...