saw your post on Bike Forums re Alsys frame info. I know its been a long time but I would be interested inany info you may have found since.
I also have an Alsys frameset in off -white apart from the handwritten style name on the frame tube there are no other identifying marks .
The frame was owned and used by the UK National Hill climb champion Dave Clarke and I bought it third hand in early 2008.
I believe the frame was made in France and there was a cycle race team in the UK who was sponsored by a French Company called Alsys. They have since been aquired by another company.
Its a gorgeous frameset and very light I'd be interested to see a picture of yours.