Dave Mallinson has produced some useful books with a CD -
www.mally.com - of English folk tunes of unknown origin. Ancient Music make dark ages period instruments including a deer bone whistle.
Of-course, there's always the English Folk Dance and Song Society
Whistles are fun, once you get the hang of over blowing, pocket size and affordable
During the Napoleonic wars the three hole pipe and tabor was popular - the original one man band with the advantage that if you lost your right hand you could still busk on the street. There's an iconic woodcut of Will Kemp with his taborer dancing the Nine Days Wonder in 1600. Short tabor pipes are available fom Hobgoblin, I've only found long ones thru American sites like Susato, unless you can find someone who can turn you one. I believe there is a ta borers society who meet
on the net.
Most folk and morris tunes are in the key of D
What is referred to as a flute is often what we would call a whistle, of variable length. Apparently the favoured instrument of prostitutes in Ancient Greece.
Recorders were popular in Elizabethan England but I don;t know how old they actually are. The fingering for the low notes is the same fo a whistle as for a recorder, it's only the high notes that require recorder players to use a different set of fingering while we whistle players just blow a little harder
All in the best possible taste