Hi Kevin
As for the first ? it's been so long since I took mine apart that i don't remember
2 Yes you have to take the two frame pieces apart. There are two angled rods that join the two halfs together, wich are screwed through the frame and into the rods. Use lots of penatrating oil and a little heat if need be to get them apart
3 Yes there is a small metal piece that goes over this, they are the same trough 46
4 I can't remember for my 40 but I just did my 46 and it was one piece of rubber that went from floor to floor, if i rememder corectly the 40 used a cloth covered weather seal
the windlace goes around the door opening not around the door molding and panel
If you need any pics i will gladly go out and take some and send them to you
Stuart