I wondered who brought this old thread up. You're authorized.
Post WWII Console pianos of 1.1 m height are only 160 kilograms, not 200. 200 KG would be an old pre WWII upright piano 160 cm tall with the iron frame. Those are much more difficult. When I was 25 and weighed 60 KG I carried half a 200 kg upright down a stairs, with three "Peakload" men who were obvious winos. The one helping on my end collapsed on the stairs, and the three of us had to carry the piano over him and down the stairs. I was the man on the low end by myself
I moved my 1941 Steinway 40 console down a single flight of stairs in 2010 when I was 60, so it is not that difficult. I'm 80 kg now but most of the excess over age 25 is flab. The man that helped me move the Steinway in 2010 has a hernia and doesn't push or lift, he just stacks up boards under the end to hold it while I shove the 4 wheel dolly under it.
The hard part of a stair move happens when the landing is not big enough to take the piano flat, that is less than 110 cm stair lip to back of landing. If you can land the piano on its bottom and turn around, that is not too difficult a move. Two men can do that easily, and a 60 kg healthy man should be fine. For landings where the piano has to go around the turn on its end, that is much more difficult. The upper person has to push out on the bottom of the piano to get the bottom end up on the cart or rug on the landing, so the man on the bottom is holding the entire weight of the piano plus some excess force while that happens. It takes a pro to not break the veneer at the bottom corner if using carpet. I much prefer a rubber covered 4 wheel dolly for those types of move.
As far as disassembly, the parts I recommend taking off every time are the music rack, the key cover, the kick plate. The top likes to swing out when the piano is on its side and should be strapped down with flat nylon straps before picking it up.
The estimator of the company that had the crane on the first move, and hadn't noticed the window frame was smaller than the piano, was incompetent. Using a tape measure to determine greater than or less than is a seventh grade skill, not rocket science.
Work rules are rather stringent in Europe, and it is hard to prove a man doesn't suffer from back pain, so a lot of worker's comp cases may arise from piano moves that really are a case of some helper wanting an easy life for a few months. Piano moves are done most successfully and economically in the US by small teams of people that run their own company.
One further tip in people to get to help informally. Short people have less trouble with the disks in their backs than tall people. I'm about 162 cm and my back is holding up nicely. Lifting has to be done with the back erect, and if it can't be done smoothly, should not be attempted. The power should come from the legs and gluteal muscles, not the back muscles. Jerking the weight with the back horizontal is for Olympic class athletes, and should have no part of a profession or hobby like piano moving. I've moved four organ consoles in here in the last five years besides the Steinway 40. They also were about 160 kg each.