Got my rolls of tape, (Thanks Maine) and put them to use this weekend. I removed the fore hatch, the week before the big rains and got back to the boat to put the new hatch in...
The tape is a tad sticky, easy to work with, and I am hoping will work quite well. As my hatch was not 100% flat to the fore peak, two rear corners of the hatch about 1/8" off the deck and around the bends for almost 2"...so I cut a 1" length and attached, that followed by a 2.5" piece, a 4" piece and so on until I built up (or down - depending on how you look at it..) the wedge needed. Then I laid the two overlapping strips on the screw line and had the admiral help me gently lay the new hatch in place.
I used the end of a papermate ink pen to cut screw holes, and use small drill bits as allignment pins to drop the new hatch on. Removed the first drill bit, and replaced with a screw, as with the other 4. The started the remaining screws. Went below to make sure that all was well. So far so good.
New hatch is in place, warming up nicely, and I will take a final turn on the screws later this afternoon.
Lessons learned...using the suggested hardware was best - called for flathead #8 screws, PO used #10 pan head sheet metal screws which stuck up in to the seal area.....MORE tape is better than less tape...I did have one small gap...that I was able to pull/stretch the butyl tape and slide it in as I set the hatch - would have been better to build up the corners more the first go round, as once placed the tape is quite sticky..
Will see how well it has sealed later in the season when the rains come again.
All the best.