Don't need to apologize, Felix! Look at how much fun discussion's been had.
If you're interested in the T-28 as a light/attack aircraft, you probably should look up the two books by Christopher Robbins:
- The Ravens - Pilots of the Secret War in Laos
- Air America - The Story of the CIA's Secret Airline.
Bit more specifically on COIN missions in Ravens; bit more general dirty-tricks air-war in A-A.
There's also a few home-movies on YouTube of blokes flying "unmarked" dark coloured T-28s on airbase and over the jungle, in between general from-the-air footage of green SE Asian jungle.
...geoff