Something for the observatory builder...

[The Warthog]

A plastic dome, with base available, at a price that's less that building it yourself.

http://www.explora-dome.com/

You may be able to get these in the UK, I'm not sure.

[barkis]

Spain and Switzerland only at present WH. Pity really, as I would have given a whole lot of consideration to the purchase of one of these had they been available in the UK. Also, the link came too late as I have almost got my shed Ob. ready for occupation.

But really that dome section would, I believe, be a big seller over here, as the other part of the building would be quite easy to construct.

Ron.