I too have the fender to lower cowl problem the same as DADS50, and my cab hasn't even been touched there. I assumed they were all like that.
That's a possibility I never considered.
In my case the fender needed to go up to get the gap even so I just assumed the replacement cowls were wrong and so I cut. Some minor gap irregularity will be hidden by the welting but DADS50's gap isn't something I could live with, factory or not.
LATER EDIT: DADS50, If you don't need to raise your fender just make a cut along the flange bend and shape it to the cowl and then fill the gap with a piece of metal. I assumed you had to raise your fender.
