Wheel spacer length ?

I am Playing about with my Front End , Brakes to bring this back on topic but was wondering if i have the correct length spacer on my front wheel. Would you ever be a Dear , and tell me what length is it !..

Sorry I missed which bike it is,
May be able to help from bits and books in the shed
All the best

Doh , Its a 78 T3 front end . Just trying to be sure my measurements are right. Thanks

I’ll try to get to the shed after work tomorrow & measure up if no one else has an answer by then.
Does your spacer have a return machined into it?
All the best

Wire wheels or cast, as it seems to make a difference?

 Ah Yes , the Question is ,, is there a difference , What is it .     And what are the dims for both ?

Hi Parodi
Managed to get to the shed.
The front wheel spindle from my T3 Cali (1975-1977)measures as;
L = 31mm
I/D 20mm
O/D 26mm
Wire wheels as you might expect,
Hope this helps

I swapped cast wheels for spoked on my Convert and found the spacers were wrong and the wheel was not centred. I had some thin washers machined in different thicknesses and shimmed the spindle till it was on centre.