The comparative table of pitch is interesting (and I think certainly proves that there is no such thing as "perfect pitch" in absolute terms), but I would be a little wary of Dr Blood's views if addressing the ability of others to hear pitch.

He is himself a concert class recorder player.

However, when my late wife and I went to Dolmetsch to buy her a new recorder we fell in love with the sound of (and came away with) a Silkwood medieaval pitch descant recorder and there were two interesting features of it. One stopped note was slightly off (but could be "blown up" in play), but Dr Blood, considering that we were folk musicians, told us that for our purposes the recorder could be considered as a "B" recorder rather than a "C" recorder - and was shocked and amazed to find that we as farouche folk musicians could clearly hear that the "C" of the recorder (at A=415) was not B of A=440.

To use it as a "B" recorder (which Jacqui used to do, it made life a lot easier than playing A flat minor on a C descant) necessitated not fully putting the first joint home. The thickness of a thumbnail was about the right gap - but then the next octave up got interesting. For some reason it was also necessary to keep the lower joint extra extra tight and I got quite accomplished at binding and re-corking that joint.