Aircraft mechanic reported installation of an incorrect main gear box on a helicopter after it was returned to service and flown.

Narrative

Aircraft X had a chip event on Day 0 at ZZZ International airport which is about one and half hours away from the ZZZ1 base. The result of the chip and oil analysis was that main gear box needed to replaced. As a result I ordered the main gearbox from Airbus and was told that none were available and the lead time was approximately two weeks. Due to the lead time it was determined that the best course of action was to cannibalize a main gearbox (MGB) from an aircraft at the ZZZ2 maintenance facility.The main gearbox that was sent did not have a hub shaft installed as the hub shaft determined to be damaged beyond limits. As such I removed the hub shaft assembly from the MGB on Aircraft X for use on the cannibalized MGB. the initial conversation about what aircraft MGB would be coming provided that the same part number MGB would be provided. Due to issues unforeseen circumstances this did not happen and the MGB provided was not the same part number. I ordered MGB; the MGB received was [the wrong part number]. As it turns out that MGB is not compatible with the main rotor hub shaft that was removed from the bad MGB and installed on the cannibalized MGB. I was unaware of this issue and did not see this compatibility issue in the Aircraft Maintenance Manual (AMM). Turns out that this compatibility chart is in the Illustrated Parts Catalog (IPC) not the AMM. This was only brought to my attention after I submitted a fresh service ticket to service engineering for the component replacement in the Maintenance Software. Unfortunately the aircraft was test flown; returned to service and approval by acting Maintenance Manager and returned to base flying a total of 1 hour and 32 minutes on the parts that were not compatible. This transpired on Day 16. On Day 17 I received a call from Person A with service engineering who informed me that he could not update the Maintenance Software compatibility due to the fact that the MGB and hub shaft where not compatible in the IPC. I proceeded to call AirBus tech support who opened a TE; also called the area manager; Maintenance Manager and Company to take the aircraft out of service awaiting the outcome of the TE. I understand that it was my responsibility to ensure the parts where compatible and I missed this. I also believe that I should not have been the single point of failure in this endeavor. If we are going to cannibalize parts especially major components with multiple variations there should be at least a second set of eyes to ensure compatibility; software update; etc. To leave all of that to the mechanics on the ground working long hours off site with spotty Wi-Fi coverage for access to manuals is a recipe for disaster.