You do not want to change the location of the tanks. The
keel tanks are a pain to clean up but they are there to keep the weight central and low . You have on most of these ,
fuel tanks up front and the
anchor locker etc and the platform over the tramp is over 100lbs alone so there is already a lot of weight up front.
On mine someone had put 450l
fuel tanks right up front for extended range and I had to cut them out through the sail locker hatches piece by piece to get rid of the weight - and in fact went down to two 115L tanks which is plenty enough and saved a ton of weight which improved sailing.
The keep tanks normally need quite a lot of attention - they get
osmosis (with water inside and out) and a lot of flaking of old gel coat etc . If they're really bad the only option is to
lift the sole boards, cut the tops of the tanks out with a grinder (its easy as its thin fibreglass) which is messy, and open them right up. You can then sand,
repair and finally
paint them with potable water safe (or aquarium safe which is the same but
sold cheaper)
epoxy to seal them. You can then glass the tops back in . Don't forget to
epoxy the undersides of the tops too and its worth adding extra
inspection hatches too.
It took me about a week to do all told and I also had to
repair a couple of the baffles that had cracked off the sides of the tanks . But once its done right its done forever if you use the expoxy
paint to finish . The tops you cut out by the way are not structural - the sole boards sit above them on a frame and that stiffens up the keels. You want to put a lip all around the piece you cut out before you put it back so it will just sit in the hole you cut and the lip holds it on place. You can then stick it down with epoxy and glass it over again at the edges to be double sure its sealed.
It sounds like a job and it is but there really aren't any other good options unless you're prepared to have tiny water tanks under the
saloon seats etc - ok if you're not going far and don't intend to
live aboard but not for cruising.
Fell free to message me - I rebuilt mine over 7 months full time in 2018 after
hurricane Irma and years of day
charter neglect left her in rough condition. There is nothing I've not done on one of these fantastic
boats. I also dropped over a ton in weight in the
rebuild which makes a big difference if you like to sail fast