I do not know of any published data on how many Daisy Legacy rifles were made. This is something you may want to ask Daisy directly. I'm listing two links for you to check, both are on the Daisy homepage.
See links below.
I believe that current made rifles are made in the state of Maine.
Puma rifles are made in Brazil by Amadeo Rossi International and distributed in the USA by Legacy Sports, Inc.
made in 1967
made in 1967
If you are asking about Daisy BB guns not rifles or any other brand made by Daisy. then I would have to say the Daisy powerline models 5502 and 5503 are the fastest Daisy BB guns at 430 FPS. The Daisy 880 and several other models reach 750 FPS. But these are rifles not BB guns like you asked in this questiion.
100 or so
100 give or take
100 or so
I have seen mention of a Daisy Model B being made in 1910.
Daisy offers a service to identify older air rifles. (It's free) See the link below
Both Daisy and Crosman made air rifles for Sears. I believe yours is a Daisy model 800 made between 1957-84. All sears models starting with 799 were Daisy's and all models starting with 126 were Crosman rifles.
Made in 1967. 97,395 rifles and carbines made.