Original publication details visible here on google books (see p. 5 and fig. 1).

I'm not aware of any further details, whether (a) the hybrid was ever verified genetically, (b) whether the any of the specimens raised then still exist, or (c) whether any further specimens have ever been raised subsequently.

If you can get it, yes, it should be better adapted to the eastern USA climate than P. lambertiana. But I'd doubt it will be hardy in zone 6 NY, unless the P. armandii parent was from the far north of that species' range.

Resin

The range of Pinus lambertiana includes zone 6 areas
in Lassen county California and Lake and Klamath counties
in Oregon.

Thanks for the link to the google book information. Gee Farms in MI has a specimen of the hybrid planted out and grafts for sale from that plant - which is why I asked. Perhaps I'll try it on my property.

On a side note, I measured the cones I collected from the P. armandii in Ithaca, NY. They are all over 6.26"/16cm; the largest is 7"/18cm. From the sources I found online, the cones should range from 8-14cm long. Could the tree in Ithaca be a hybrid? Or maybe var. mastersiana (which is supposed to have cones up to 8"/20cm)?

Pinyonhead - that's intersting to note about the sugar pine. I wonder if the populations in those areas would perform better in the eastern US? I would assume summer humidity and consequent fungal problems would still be their downfall.

"On a side note, I measured the cones I collected from the P. armandii in Ithaca, NY. They are all over 6.26"/16cm; the largest is 7"/18cm. From the sources I found online, the cones should range from 8-14cm long. Could the tree in Ithaca be a hybrid?"

The sources you found are wrong ;-)

8 cm would be abnormally small; they are not usually under 10 cm, and regularly reach 20 cm long. I've seen reports of cones up to 23-25 cm long from the south of the species' range in Yunnan and Burma.

Just checked Rushforth's Conifers, he gives "7-25 cm, mostly 12-20 cm"; I'd go with that for an accurate statement.

Resin

Resin, good to know, thanks!