Putting early bug pop outs back together

Sorry i know its not very cal look, but i'm really struggling with this, and its sending me nuts!!

I brought some early pop out's ages ago, and although there in good condition they need putting back together, as they been completely disassembled.

I'm trying to get the glass and rubber inner seal back in the ali frame, but really struggling. Tried lubing them up, but I just can’t seem to get the glass/ seal back into the aluminium frame channel.......

Any advice on how to get em back together would be mucho appreciated?

Or if anybody knows anywhere that could actually do this for me (in the UK) that would be great too, as I really don’t want to knacker them.

Cheers

Dude