The engine area is much more detailed, 10221 looks half finished in comparison. The top city is massively more detailed, with a large range of different elements utilised - 10221 mainly uses 1x1 round plates and 1x1 plates with clip ring over and over. There is a to-scale mini Imperial Star Destroyer with it.
Since I've owned this model I haven't seen a single other one on any UK forum or FaceBook Lego page, it really is a very rare item. The set is broken down into labelled sections as per the photo, and will pretty much build straight to the instructions from each bag. Please don't waste my time or yours with silly offers, the parts alone cost more than the price I'm asking, plus it took a couple of months and many Bricklink orders to collect all the parts together. Collection is more than welcome and ideal, but I will also send via fully insured 24hr courier.
Any questions feel free to ask, thank you for looking. The item "LEGO Star Wars Custom UCS Super Star Destroyer. 3200 Parts, 124cm Long" is in sale since Monday, January 16, 2017. This item is in the category "Toys & Games\Construction Toys & Kits\LEGO\LEGO Complete Sets & Packs". The seller is "shaza333" and is located in Sheffield, South Yorkshire.
This item can be shipped to United Kingdom.