here is a link to Johnson's website and the 118
http://www.johnsongas.com/industrial/frn-solder.asp
I redid one many moons ago, used a Rutland castable refractory, since then have bought bags of Mizzou mix from AP Green/RH. they originally had a chicken wire re-enforcement which I had so put it back.
Just be aware the old refractory could have asbestos, don't know how old, but be safe wet it down, use proper respirators and clean and dispose of everything properly.