Miles - regarding the layout and entirety of buildings, engines, cars, track etc, just make sure you do an inventory and do an estimate on what each piece may sell for or leave it at purchase price. Having been the executor for my mom's and mother-in-law's estates, the biggest challenge was figuring out what might be of value and what wasn't. The cleaning out the houses to make ready for sale was a huge time commitment. Make sure the next person knows there are auction houses out there who will buy collections and come in and get them. A couple of years ago one of them (Stout?) had a large layout for sale, buyer had to come in and disassemble. Do not remember how that worked out. Personally I would not down size in preparation for my next adventure? Seems to me that is too much like waiting to die, none of us know how much time is left. Have excess stock you don't run or need that is another story. Maybe sell those off now. Otherwise keep doing what you enjoy. Having an inventory to share with the auction house will make it easier for them to say "yes we'll take it" - they will have an idea if they can cover their costs.
When I had my house under contract the buyers insisted the train room be "clean" and had a separate clause in the purchase agreement. No value in the layout to them. Nor was there any value to me because I wanted to build something different in the next house. Took me about 8 hours to strip the layout and cut it up enough for the trash guys. Actually, my biggest problem was getting rid of the plywood and other materials. If it did not fit in the can, they would not take it. I got very creative in getting rid of pieces. Yours is quite a bit larger than mine and may take a small army to disassemble. Hence - the auction guys who will do a lot of that work.
The after take down photo, the next one image of the layout - grandson not included in the sale.
Best - Jeff
