Our 1980 KP44, came with a supporting beam running under the inner forestay base. The dimensions are approximately 2" x 4" and it looks like a factory item in that it is clad in the same teak as the rest of the interior. We added an ABI Forestay Release Lever Base which matches our ABI "Inner Forestay Release Lever". The Lever Base has a boss which projects through the hull and has a 5/8" threaded hole set at a forward angle. A tie rod or cable pennant can be connected at this point and led to the anchor locker base.
The inner forestay fitting is a standard ABI Foredeck Release Lever Base (below) designed to accompany the Forestay Release Lever Base. It has a boss which projects through the hull and is internally threaded for a tie rod.
Because the projecting boss cannot go through the beam I had a stainless angle bracket and backing plate made to fasten around the beam and allow the boss to project through the deck. This meant moving the inner stay forward 5" but this doesn't cause any other problems except I needed a toggle to lengthen the stay a couple of inches. If you don't have a supporting beam under the deck I think it would be fairly easy to make one if you are at all handy with wood and fiberglass.
Stander, s/v Beatrix