I just bought a wooden flute at a second hand store. It appears rather old. Three pieces, with the bottom two being blackwood and the mouthpiece of some polymer (I think). It has six keys. The finger holes are silver lined, rather than just wood. The initials HR appear on the middle wooden piece. It’s going to be a week until I’m reunited with my camera and computer so I can’t post pictures yet. It’s got a nice tone.
Given what I’ve described, can any of you identify what I bought, who might have made it, etc?
No. It means “High Pitch”. Short of seeing the stamp, I agree with David that that is the most likely stamping that would look like that. Its exact import is another matter: to the Germans and French “HP” could mean something close to our modern pitch (A=440Hz) and “LP” meant lower, A=c432-5Hz: whereas to C19th English players (and mostly to us now) “HP” meant A=c445-450 and “LP” would have been 440.
We can’t say much more until you can post the pictures, I fear. Overall, sounding length and C#-Eb length would be helpful in making a diagnosis too.