(31 Jul 2016, 8:21 pm)Tom wrote Why were 6134/6135 swapped to 3995/3996? Sorry if it's been mentioned before but I can't remember it.
They are slightly taller than the other as they were formerly convertible open toppers.
(31 Jul 2016, 8:25 pm)biglugs@yahoo.com wrote Because they were formerly open top
They were convertible open toppers not full open toppers.