What is needed is a large block moulded into the hull at a height that goes straight to the winch from an eye as said above.
Here is a way to get that block into the forward tank!
Drill two small holes into the bow the same distance apart as the bolts in the eye bolt you are using.
Thread through these holes two lengths of string and find a way to pull them through the hatch hole.
Shape a block to fit snugly into the the bow,this being about four to five inches long and drill two small hole in it the same as the eye bolt.
Thread the string through the block plus more so that you could pull back the block if needs be.
Cover the block on the side to be glued with epoxy glue or whatever you like to use for glassfibre work and pull the block into the tank and up to the bow,the holes should line up when the block reaches the bow.
Hold and wait for glue to dry.
Now either screw fitting to bow or redrill holes and bolt if you can find a way to get to the bolts.
Good Luck, It does work !!