I've been owning and playing Roscoe's since the mid 90's and I can't say that I've noticed any definitive change in the feel of a Roscoe neck.
Of course I've always loved them and would have never thought to describe a Roscoe neck as thick.
Gard will chime in when he wakes up this morning. He'll know for sure. I suspect that he'll say that they all differ ever so slightly, due to the finished hand carving, but that they should be relatively the same as yesteryear.

Maybe you played a special ordered bass.