I does not seem like it was "adapted", the PO said everything just pluged in and ran. I only heard it run for a few moments while using starter fluid, the tank and pump were fu**ed up. I'll try to get some pics soon.
Im guessing that an ECU and harness would be cheaper than a 1.3 intake and TBI. This is getting interesting.
Running a 1.3 intake and TBI on a 1.6 usually doesn't work real good. Some people get it to run ok, but others don't. I would match the intake and TBI system to the block being used (1.3 to 1.3 and 1.6 to 1.6). You will also need to match the wiring and ECM to the intake being used. You may be able to mix and match 1.3 and 1.6 parts and get it to work ok.....but I would either run all 1.6 stuff (engine, wiring, ECM), or all 1.3 stuff(engine, wiring, ECM), if it were me.
Did he say why he put the 1.6 engine in? Did something go wrong with the 1.3 stuff, or did he just want the bigger engine? What did he do with all the 1.3 engine he took out?