Thanks for all the nice comments! They are very much appreciated.
Yes, my set up is not normal. I have long legs and a short torso, so I need a shorter top tube usually with a lot of seatpost showing. On all my bikes, the measurement from the center of the bottom bracket to the top of the seat is 83-85 cm, depending on the bike.
I was very lucky to find the frame in such nice condition and the seller was willing to ship. I originally didn't think the deal would come together, but the seller was great, and shipped it via bikeflights with no damage.