Measure the aperture. Around the metal frame with a bit of string. Unless it is nearly new, I suggest not using old seal.
Then contact Seals Direct with thickness of glass and body metal. Likely 6mm glass. 1.5mm metal. Gap (web) 7mm. And length required. Plus the filler strip.
Is the old seal Claytonrite (looks same as in link) ?
https://www.sealsdirect.co.uk/shop/wr65-19634
There is a how to fit tutorial on their website, too.
My preferred method is to fit rubber seal to metal frame with gap at centre bottom. I knock it with a lightweight camping mallet to be sure it's fully seated all the way round. With a sharp craft knife carefully cut seal to size, making it as snug a fitting as possible.
Now spray a mist of soapy water around glass gap. Fit bottom of glass into seal and use a fitting tool (a small wooden or plastic spatula will do) to carefully prise seal over edge of glass equally on both sides and then across the top. Make sure glass is fully seated in seal by gently knocking it with palm of you hand.
Now the awkward bit. If you dont own a special glazing tool, fitting the filler strip can be a chore to insert. But is still achieveable using a flat blade screwdriver. Warning! Paint work can be easily scratched using a screwdriver. Guess how l know
Special glazing tool.
This time start at centre of top of seal, opposite and matching the place where seal was cut. Spray with soapy water and feed strip into gap. Cut excess with a sharp craft knife.
Good luck.
