Weight
I can only quote civilian Chinook figures but I doubt they're very different. The BV234 hook was rated at 28000 lbs but in practice, due to the aircraft APS weight, the figure that could be lifted was about 20,000 plus. On one load we had requested a water tank loaded to give 18,000lbs. Oweing to an error in the tank gauge we eventually lifted 23,000 lbs and that was right on limits. The military Chinooks have a higher MAUW but even 18,000 lbs capability would be more than adequate for a stripped-down 61 which might weigh 13 - 15000 lbs assuming zero fuel and depending on role equipment.
In extremis, I suspect a Chinook could lift a laden Seaking (minus crew) given reasonable ambient conditions but I stand to be corrected.