Ken...I am using lime putty now as we speak;
 mixed with sandblast sand; and a little portland...1 (lime ) 1/2 sand  1/8
portland-.remember ...the properties of portland  are a blend of clays
processed and refined but can be found (almost ) in a natural state.(here in
the south)..lime (putty ) sets by air...so it is always setting ..and has
give. When you take apart stone set in lime clay; you can quite often damage
the stone getting them apart;; we took apart a low stone wall at Columbia's
old engineering building; where a 22 ton crane picked up blocks of stone set
together with lime and had to be dropped so they would come apart (they were
not being saved ) but demonstrated the enormus strength of the bond..odd you
should bring this subject(Inca) up my brother who lives in S>F has a client
who just bought a small tourist hotel  and an large scale Inca ruin in the
mountains of North Agentina and is contactiong me about stabilizing the
ruin...HAVE  TROWEL WIII TRAVEL  ...what about it Kimosabees..you bring the
fly rod the s"mores ..M