I once had a argument with a couple of the lads I worked with at Armstrongs.
It was about the difference in the inside height of an FL10 & a F10 & believe it or not but from floor to roof there was only about half inch difference.
1st pic me FL7 2nd Geordie Truck Show Witton Castle
3rd pic 2nd moter 113 was mine & the 3rd one might be of interest to you 43`rs out there it was a143 500 no Plate was M500 - ■■?