If you search this forum's archives you'll probably find more about Marcel Calborn and his shop in So. Calif., now in Laguna Hills, I believe. He's still in business and answers the phone, but has not much interest in the old bikes. Yours was probably built by one of the same shops that made Colnagos of the same ('84ish) vintage, and the geometry and specs are often nearly identical, though the Celos seem to be a tad more conservative: flat fork crowns, less/no shaped tubing...an SLX should be a brillant ride, enjoy it!