That rigging by the stacks is bit challenging. I ended up gluing down (with fast drying glue) to help hold. They were not as tight but it would pull at pieces if too tight
Glad you’re enjoying it! I’ve built this one a couple of months back and it’s such a filling and satisfying build, isn’t it? Yours is looking nice and smooth so far!
Regarding the strings, I honestly wouldn’t say it’s that challenging once you get the way of them, which you should after one or two of them. My personal advice would be not to cut the remains of the strings when the manual prompts you to. Instead wait until you fit the chimneys into their “holes”, since they tend to move and “relax” the strings because of the pressure and movements you use to fit them, so you can re-adjust them afterwards and then, then you can cut them. I didn’t do that and some of my strings are not that straight now.