110 is a putty that you could use to bed the foam in place.
No, 110 will not work with cloth.
You will only need a pint of the gallon to bed the piece.
You will need to buy resin for the cloth. Use cabosil to thicken and use that to bed the piece in place.
3/4 of the gallon will go to waste. Return it and get resin.
WS 105 is great stuff but expensive.
www.raka.com will save you money on resin and cabosil.