Karel I hope you consider this in the spirit in which it is intended................The seat post out of the top of the frame actually mounts to the 'double bump' withthe two holes. The rider can adjust between the two holes to suit. You will see the clip # 51920-29 this pops off the screw #51918-29 and the seat will pivot forward for battery access. Compare #51900-30 to the kit part #25c . The front of the seat is bolted to the oval shaped hole in the bracket. The bracket in the kit is the problem. This is a copy of the actual HD manual for this bike ,for my bobber I copied large parts of the manual .There is also a book 'How to restore your Harley Davidson' Motorbooks International Authentic Restoration Guides ISBN # 0-87938-934-6 . This book is almost required as the author is restoring a WLA and contains vital info for all early harleys. I wonder if Italeri did this on purpose to wreck the 'look' of the model ,as you can see it does not say Harley-Davidson anywhere on the kit box or contents. I feel this neccessary because I see these WLA models and it drives me out of my mind to see the inaccuracies !! A little trivia -any number shown followed by -39 ,the 39 is the year of the first use of the part . Again -excellent work on your models!