Just a question for the more knowledgeable members out there. Is a Heuer Autavia (manual wind) 73363 or 73463 in Siffert colors considered to be a collectable "SIFFERT" by the Heuer community? I've seen these go between $5500 - $7000 recently. I know the 1163 with Cal. 11, Cal.11i or Cal.12 is considered a Siffert and price is somewhat dictated by dial execution and age, with the Chronomatic labeled dial being the "holy grail". What drives the price of the manual winds? Availability? Was curious about your thoughts on these watches (73363 & 73463) of the same era ('70-'72) with the same Siffert color scheme of blue accents and blue seconds hand. Seems that both with and without date fall into the same price range. I believe they have a Valjoux 7733 or 7734 for date version. Thanks - Jeff