I might go ahead and run water pressure, as for water temp the Mercury Flagship gauges only have a C-H type gauge. I would rather have some numbers, but its no big deal.
Looked up parts for rigging, and i bout had a heart attack when i seen the price for a outboard to remote harness $280 for 20'. That might be the only used component i use on rigging if i can find one used.
The Rapture props are no longer made. They have been replaced by "Apollo". The 21 might make a spare. $280 for an Apollo stainless prop. Both Rapture and Apollo are Michigan wheel props.
Destroyer if you decide to run premix i can take that oil injection off your hands.