Just spoke with Grove: airfoil gear not discontinued
I just got off the phone with Gail at Grove. According to her, they have not discontinued the airfoil gear. Grove currently have a very large contract which they are fulfilling, and have no capacity to slot this product. Therefore they don't want to take orders for it right now; hence it's been dropped from the website for the time being.
I asked if there was any size order which would compel them to build now, and she said no - there just isn't any capacity.
Gail said they like to run minimum batches of 15. They have a call-back list with 11 names on it (including mine, now). When they are ready to resume production (and assuming that have not, at that time, decided to discontinue), they'll give the folks on the list a call.
I would encourage anyone interested to call and get your name on the list to register interest - that could dissuade them from possibly discontinuing prior to running another batch.