You may want to think twice about "finishing" the silk top. A newly quilted old top becomes a new quilt and if the top is of unique design it is frequently much more valuable left "as is". Both sides of the issue are found here:
http://www.quiltersreview.com/articl...t/010409_c.asp
This would be especially true if the silks are cigarette silks or if the top was intended to be a crazy quilt. Victorian crazy quilts had no batting and no practical purpose. They were simply "for show" and were not really quilts at all. Learn more here:
http://www.quiltersmuse.com/crazy_quilts_in_America.htm
A local antique dealer, quilt appraiser, or even a knowledgeable quilt shop owner can help you determine whether it would be better to leave the silk top alone.