Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
On my 400 & 500 I found that when the engine is in place with the hope that the carbs will not have to come off again fitting the carbs then building back works well. The battery box is a puzzle to fit into the frame, having the rear front half mudguard out just makes life easier with less collateral damage to your knuckles & patience. 😁
All looking good so far! Really good to see it taking form. Can I add to the good advice above (and sorry for stating the obvious) a good idea to have the carbs held in position and flooded with petrol just to check integrity of float valves, and carb float bowl seals etc.