Just built a new companionway hatch for my Newport 30 last winter...had similar issues...used the old frame as a reference and constructed a new one out of clear spruce (nice and light), and topped it with farm teak T&G flooring (3/8 inch thick and you can get it pre-finished ) for nice looks. When you try to duplicate the frame, make sure you pay attention to the angles for the slide and the clearances underneath for the supports to slid back over the lip at the rear of the companionway...I didn't and it "ticks" a little when the center support slides over it. the old hatch frame was teak, with a teak T&G top and was about twice as heavy as the new one.
Skipper (when my wife lets me)
S/V Das Dawg Haus