Hi,
I'm not a specialist, and I can't tell what is the chassis. This forum is more specifically dedicated to Haynes Roadsters, and even if you will find here people with a big experience of kit cars and "7 like" cars, may be you should also try
http://www.locostbuilders.co.uk/
where, (for having been on this forum before), you will find people from a lot of different horizons and building very different cars (all 7 like kit cars, but much more). You should try to post you pictures on this forum, and you might have better chances for identification.
Hope this will help.