How to fix perspex sheet over window opening?

[MarionK]

Company sent opaque perspex instead of clear polycarbonate, so it's only a temporary fix, so I'm thinking it's probably best not to use sikaflex to seal as it will need to be cleaned off again in a few weeks time. The original H section rubber seal is still available, Otherwise, it's just a hole with wooden infilling between inside and outer wall of the mh. I do have a bunch of nice screws with plastic 'washers' and caps, but I'm thinking that the rubber seal, holding the sheet slightly away from the outer wall, will make for a lot of stress around any screw holes.
I guess it's a matter of figuring out which is the lesser of the two evils. d'oh! Just realised also, that the screw holes would need to be sealed.
Anyone ever tried anything like this?

 

[AndyPK]

Er……why are you doing this…….?

 

[MarionK]

Because I couldn't get proper window replacements.

 

[Spriddler]

For a few weeks I used gaffer tape on a piece of hardboard cut slightly oversize whilst waiting for the new window to arrive.
It wasn't pretty but it held at all speeds and was waterproof in a lot of heavy rain.