Houlio you had to enlarge the diameter on your windows. But if you were to use the old rubber over again, they should of fit right in. If Gror's windows, rubber, & openings are original, & he replaced them with new rubber of differant thickness between glass & frame, wouldn't it affect the end result
Example :: glass diameter is 6", opening diameter is 6 1/4". Your new rubber can to be no thicker than 1/8th of an inch. If the rubber is 1/4 " thick, it's too tight!!! By thickness I mean the distance between the glass & the wood.
Another thing I had to do with the glass on my windshield was to put a small bead of butyl rubber in between the rubber & frame & glass to reseal it tight.
That's what I meant by determining the size. Try it with a piece of scrap plywood first!!!