> Has anyone any experience or knowledge of getting bees to live inside a
> perspex container - in addition, getting them to climb up to a roof?

I've used plexiglass (similar to perspex) for observation hives, and
you may have simply not given the bees long enough to adjust.
After a while, bees learn to climb on just about anything (glass,
aluminum, whatever).  I have yet to find a surface that is impossible
for a bee to navigate, gum up with propolis, and force me to clean.
Glass seems to be less prone to being gummed up than plastic, but
they will always do a very professional job of "caulking" at the edges
and joints.

I've never made a "roof" from plexiglass or glass, as I tend to make
the "roof" 100% 8-mesh with a sliding cover to prevent overheating
and also prevent excessive heat loss when appropriate.

The bees climb on an 8-mesh roof with both style and panache.

        jim