Same old same old, but on a different tack. Loft insulation in a house built in the 1930s. Its a 'Vermiculite' like substance and without second guessing, does anybody know what they used back then for loft insulation?

It doesn't sound like it, but you won't be going ahead purely on the basis of what we say will you? However, if the material is loose asbestos in some sort of granular matrix then you've got a real big problem!!! HSG264 Appendix 2 gives a good 'potted history' of ACM uses, but it isn't exhaustive. The date of the property may have little relevance or correlation to the date the insulation was put down. Loose asbestos insulation for this application was usually bagged. If you can see shiny mica pieces then the material is likely to be modern, akin to 'supalux' material.