Brian,
I too need to replace the screen in my front window and bought the tool
to roll the spline into the slot and it may be what you're looking for too.
I have in my hand the very tool I bought at Builders Emporium. It's made by
the Phifer Wire Products company, called a Screen Installation Tool
Di-it-yourself. It's in a blue and white package. The part number shown
beneath the bar code reads: 047888098750. I did go to their web site,
alas, only to find that they don't even list it but what I did find is an
instruction page for installing screen that shows their tool in use. You
can see it at http://www.phifer.com/rescreen.htm.
Here's hoping that this helps. By the way, I bought the wrong size
spline when I got the new screen material and will be going out today to get
the right stuff. It looks like the slot in the aluminum around my window is
smack-dab on 1/8", the exact the thickness of the wheels on the installation
tool. One tool has a concave slot in it's circumference and the other is
convex. The referenced instructions above explain it all. I can't wait to
do it now, thanks.
Glyn Judson
1969 Caravel #508
Santa Monica CA