I believe only the early 1939 models had aluminum hoods, before switching to steel later in the year. This is indeed a rare item. Though I would never pay that much for it, it's obviously worth that much to someone!
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Yep.. aluminum hood, horizontal bar grill and steering pedistal were early 39' workarounds that ford used till it's metal pressing equipment/process was up to speed for the steel skins. IMHO.. that's a high price... You can occasionally find a whole non running tractor with 1 or more aluminum pieces on it for at or under 1k$