This is all very interesting, I always thought my 2446 was put together from spare parts as it didn't appear in the OTD model guide. Mine has a serial number 833XX so not so far away from the range suggested. Sure, it's a bit of an old dog but I love it. It's currently having some repair work done and we're going to see if the dial will clean up and if we can find some replacement sub dial hands. At one point I seriously thought about breaking it for parts, I'm happy to see it is a genuine Autavia. At least I think it is, what do you think?