Larger leisure battery on early Nuevo.

Has anyone fitted a larger leisure battery in the under seat space space on the early Nuevo? I've found for length(26cm) and width(17cm), the largest capacity battery that will fit between the fixed supports of is an 85AH.
 I can grind off the welded width plate support to gain an extra 5cm, and re-tap the side studs to gain another 5cm in length, but the height(24cm) is non-negotiable because of the seat plate.
I'm searching for something about 100AH, but as yet haven't found anything suitable.
Al.

I had similar problem when I had my Nuevo. It had only a 75amp, anything bigger didn't have the shoulders for the clamps so I had to get a old fashioned battery clamp (the type with a length of angle iron and two threaded rods with hooks at the ends) and got an 85amp , so probably same as you've got now.