I have a 20ft 88 appart right now. I took my tank out. The manufacturers label still on it the company is still in business under a new name in same town in FL. I googled it .
They had the plans for all three 20 ft models . You can pick yours out by the hose pickups and the gauge.
I live outside of Boston and knew a good welding in Plymouth ma. Capeway Welding Ron Peck . since he was only 40 miles away I just brought him the tank and he duplicated it. Pon is very knowledgeable Had the neprene Rubber for Banding/securing tank.
HE walked me through the whole process . He was about the same price as florida outfit and I didn't have to worry about shipping. It will go in this weekend .
while you have console off & Deck/hatch off. you ought to think about the resecuring of console. My screw where all loose ,caulking was holding them in
I dried all the holes and filled them with west epozy
with adhesive filler. for the forward three bolts I cut a 5 to 6 in inspection circle in the fwd wall of tank
hatch . buy the Beckson hatch first and trace it. Then you can get in under deck . I took a Strip of Hard mahagony ( starboard & epoxy don't likre each other so I went with a hard Mahagony). I had in my barn and 2 1/2 inch wide 3/4 thick and about the length of a 2 inches past the outer screw holes . I lined up the wholes and attached t Nuts to the mahagony after I epozyed entire piece of wood . Once everything was dry I Lined it up and put west 404 adhesive , big dab of it between holes, I then slid it through inspection hatch and secured it with 1/4 20 bolt with a washer . Once you secure it you should take out each one separately to be sure no epoxy is on the threads. When everything is dry you can secure your console with 3 bolts in the front.
for the three rear holes I just epoxyed a mahagony
strip on the underside of the hatch over those wholes. I didn't bother with t nuts on aft end. Iam just going to screw it in With the regular deck size then the 3/4 strip that should give you a substantual material for screw.
I have to get back to work. Good luck.
