Oh, the trans cooler should be on the driver's side of the radiator. There will be a top line and a bottom line. I've been told that the cooler lines on a M1009 are metal; on all the civi vehicles I've serviced, there were 1/4"- 3/8" rubber lines connecting the metal lines to the inputs on the radiator. The cooler is hidden inside the radiator's side 'tank' space on the driver's side. You should be able to disconnect those lines from the radiator, and either cut and flare them for rubber lines, or add brass fittings to accept the rubber tubing. If you like, you can put threaded plugs in the old cooler's holes to seal them. A new radiator will come with those plugs in place, since it's usually not worth the parts store's time to build a radiator for manual and one for automatic, so they all come with the cooler. You'll need to refill the trans fluid after installing the cooler, but be sure to get the trans fully warmed up before final top-off.
Under the vehicle, there should be 2 similar sized lines coming off the transmission. If they are rubber, and are old, this is a fine time to replace those. Just replace them one at a time so that they do not end up reversed.
The factory cooler type is constantly bathed in engine coolant, and referred to as a "oil-water" type cooler, since the hot trans oil gives its heat to the water coolant. The water coolant then releases its heat in the "air-water" cooler that is the radiator itself. You'll be converting the transmission to an "oil-air" system when you install the trans cooler ahead of the radiator. Don't worry about blocking part of the radiator's air; you'll be making the system more capable overall.
I don't have a MV, so sorry for some of the vagueness in the posting. Best of luck with your modifications and your trip!