Do Mk1 Astra GTE seats bolt onto Mk2 Astra subframes?

I think I heard that they go straight into Nova's, and I know that calibra seats (which share the same subframe as Mk2 Astra's) dont go onto Nova subframes without a bit of welding.

So would I be right in thinking Mk1 seats wouldn't go straight onto Mk2 subframes?

Anyone with more info than I have? anyone done it?

Chris.