Wow. Not encouraging.
My seed source, Hong's Landscaping in Wichita, Kansas has had regular fruiting for many years. But Mr. Hong doesn't remember his sourse nor does he remember how long he has had them. His 2 bushes, not really trees, are about 3 M tall and 5 m wide, with many trunks each. They are by a fence where they get no attention. They are of no importance to his landscape business, nor to his mostly beautifully landscaped grounds.
I have 5 year old seedlings from seeds from these to bushes. Sounds like it will be a while before I'll be getting my own seed or pollen. Well, I can drive 140 miles to get pollen if I have to. But first my citrus will have to grow a while.
I have been promised a grafted precocious P.t later this summer, but it sounds like any resulting seedlings will take quite a while as the precocious is recessive.