Door and window seals

I'm trying to fit new OEM 2800CS door/window seals on a 2000CS. In theory, they should fit. It appears that the piece that goes up the A-pillar and along the top of the window is longer than required - based on where I think the V-shaped sponge junction piece will end up at base of A-pillar. Has anyone had the pleasure of installing these pieces? Did you end up cutting off a small amount at the rear quarter window frame? Any suggestions on how to make a nice straight cut?

These are notorious for shrinking, right where it ends at the rear quarter window! Squeeze all of it on if you can and trim only if necessary.

The V-shaped sponge part has only one place to go properly. You can see exactly where it goes, with its little tab.

Begin by mounting the lower section, beginning at the top of the "B"-post and work down, forward and up. Make sure to get the corners correct by pressing hard to reach into the corners... I have done a few, and the end part, which is the V-shaped sponge bit, falls naturally in place with no cutting. It needs to be properly glued.

The top section of the seal is the real bummer. Hard as hell to fit into the mounting plate behind with its tracks to hold the hard plastic base of the seal.
This part is always too long. To cut it, I use a metal saw.
Then there is a small "stuffing piece" at the end. This can be done in several ways. Just make sure it seals the top of the door glass with the top of the 1/4 light glass against the roofline.

I also have and work on 60s Jaguars and the spare parts for those, incl rubber seals, are a nightmare compared to what we can get for the E9....