Rear window blind/material (2000 Topaz)?

The blackout material in my rear window cassette blind has torn.

I'm trying to find either a replacement for the whole cassette blind (635mm wide x 520mm high) or, since the mechanism is in good condition, some replacement material (approx 602mm wide x 580mm high)

I'm struggling to find either . Can anybody help or advise?

many thanks

Answering my own question and putting information here for the next person to search!

I couldn't find a replacement so I bought this Seitz 600x610 blind from O'Leary and trimmed it to size: [You must be registered and logged in to see this link.]

It doesn't fit exactly into the recess but it does the job very well. You can see from the photos that with the blackout blind down it still lets a little light in. That doesn't matter to me because at night I keep the sliding door closed to contain the *ahem* fragrant aroma from the toilet! From the outside you can't see in i.e. it is private.

The blind is a simpler mechanism than the original and feels more robust. It is slightly heavier and I'm a bit concerned that it is only held in with two screws at the top - this doesn't feel like a strong enough fixing in the plastic surround. We shall see.

I've included the window and frame measurements for reference.

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