I know next to nothing about twins, but looking at some other pilots who bought them and regretted it all the way to their bank, it seems to me that the worst combination is for a novice pilot to buy a piston twin, especially an old piston twin.
Novice owners get shafted on almost every corner in GA business, and buying an old twin is often buying a huge can of worms.
Many twins have worked very hard in their life, and many seem to be operated on the basis that if enough works to hang together then it's ok to fly. This is not the kind of machine to buy into if you don't know anything about the tech stuff.
In this case (a syndicate) there needs to be somebody who really understands the machine, and the share buyer needs to understand what the group fund covers, or not.
Also many old piston twins are worth only the remaining engine time before overhaul, and the instant something goes wrong with an engine, the whole plane becomes essentially worthless. Something to remember.