Currently working on a 1987 Specialized Sirrus frame. Was a bit disappointed when I weighed the bare frame at 4.5 pounds, as I have some in the 3.8 to 4.2 pound range. But, I was pleased to find the fork came in at 1.4 pounds, while some of mine run 1.6 to 1.8 pounds.

if the bare 653 frame/fork is under 6 pounds, you should be able to reach 27 pounds with a similar build to what you had before. Don