Thank you Jupiter.
About the only thing I have found about Masm 7 (
link) actually mentions v7.00.9466.
I did find v7.10.4035 inside the DDK from Microsoft (looks like this will be replaced with WDK which is not quite in beta).
MSDN docs on Masm appear to reflect this newer version as it has the added command line switch /safeseh.
Thanks again. I already have 3 different versions of ml so why not another one.