Can you help me upgrade from Joomla 1.0.x to Joomla 1.5

No. Sorry.

There is no upgrade path between Joomla 1.0.x and joomla 1.5.0.

There is a migration but we have chosen not to undertake any site migrations using this method as your site will never be the same and will require a lot of work to get the same site you had in Joomla 1.0.x

We are happy to upgrade any Joomla 1.0.x site to the latest Joomla 1.0.14+ version - but we will not migrate you to Joomla 1.5 - we will turn down all work like this

I hope this makes our position clear - and stops me having to repeat myself over and over in email replies :-)