You can also check pitch with the tuning reference on my website (I give up with trying to post URLs here - use http colon slash slash tinyurl dot com slash 9xvdp).

If they do turn out to be A=415 models hang on to them! (I have one of the very few cheaply made recorders at this pitch - it's bright purple transparent plastic with metallic glittery bits, so it's pretty obvious when I'm playing in a strange key).

Not all recorders have the "forked F" fingering. The ones that don't are "German fingering" models, made in Germany in the mid-20th century. These make the F easier to finger and everything else more difficult. I have one, in an unusual pitch (A) - unless you have a very special reason, you ought to avoid them.

The essential difference between recorders and whistles is the octave thumbhole.