For Mother's Day, I took myself to the House of Musical Traditions and scored a bamboo quena. It's a notched, end-blown flute (NEBF hereafter, because I am lazy). Since I have no experience in making instruments of any kind, I thought I should get a real NEBF to see if/how I could play it, and how it was made.
I can get sound out of it, but not really reliably. Progress! But need practice. With this as a template, I can measure off proportions for trying to make a NEBF out of some PVC pipe I picked up at the hardware store.
I think I also need to lay hands on an actual archaeological report (or two or six) documenting some of the actual Anglo-Saxon flute finds. I think I've sort of assumed that because I saw one bone flute in the news that was a NEBF, obviously all early bone flutes were the same. That might not actually be the case.
Graeme Lawson's website lists his publications, which include analysis of several Anglo-Saxon flutes. None of them are easily available (read: free and on the Internet) but I can check my local university card catalogue and see what turns up.