Hi Clutch, according to the parts manuals that I have got only the rocker covers are identical. So that should be quite a gamble I guess
Mister Bill Murar can tell you more about the subject for sure. He is a well known expert in the USA on Sears/Allstate machines.
You can find his contact information at the Yahoo group mentioned above, and a list of available NOS parts for your 106 too
Have you already disassembled the stuck engine and do you know which parts you need? Because I noticed there are some Gilera/Sears 106 parts offered on ebay USA at the moment.
A famous address in Italy for pistons and rings is "The king of pistons"
for more info.