> How long did it take it for the Osprey to make it into service?

I was curious so I went and looked;

1981 - Initial development contract awarded

1983 - Bell/Boeing submitted their prototype and since it was the only submission, they were awarded the contract

1985 - Osprey designation established, first full size prototypes under development

1988 - First Osprey was finished

1989 - First testing of the prototypes started and first flight in helicopter mode (several of the prototypes crashed)

1994 - Bell/Boeing received production contract for EMD phase

1997 - First EMD flight + more testing

2005 - Full rate production authorized

2007 - Marines began fielding them

They were still testing the various modes (carrier onboard deliveries, etc) into the 2020s but the most favorable case is that it took over 25 years from prototype to service.