The build book is certainly a 'nice to have'.
I think it does make a difference if and when you sell the car and also it is nice to show friends and family when talking about the car
The reason I say it makes a difference when selling is that it was certainly a deal maker when I bought mine
It just helps to reinforce the provenance and also makes a potential buyer realise that the car was a cherished purchase and makes it 'special'
If you have absolutely no plans or wishes to ever sell then it is still nice to get out and have a little look from time to time
It sometimes comes out when we have vistors who are interested in the car
