Hi, Russ,
Truly a great looking L-4!
I own L-4A Sn. 10371, 43-07080, delivered 5-28-43, with just over 3,700 hours on it.
I can heartily recommend a wooden prop. Wood has some real advantages over metal. First and most importantly, it's correct for the A/C. A wooden prop will last virtually forever. requiring minimal additional annual maintenance. If you should ever have a prop ground strike, the prop will shatter before the crank shaft can be damaged, so you don't have to disassemble your engine to check the crank's run out. Wood absorbs all engine vibration, so power is delivered with turbine smoothness. Lastly, it's classy and looks just right. It's like flying along behind a fine piece of furniture. When the sun is just right, all you can see is a shimmering brass colored disc out front. Magical!
The original prop was a Sensenich W72 CK 42. I use a 44, as I get slightly better performance at cruise with it, about 5 mph indicated. Sensenich makes both models today, correct down to the green reinforcing fabric paint.
I've owned the L-4 since 1996. I took it apart in 1998 to correct the paint scheme only. This, of course, lead to what amounted to a major two-year restoration!
Linked below is a photo of 43-29080. That's me in the hangar, sitting in a '43 MB jeep, Sn. 236426, delivered 5-20-43, eight days before the L-4. The jeep "lives" under the wing of the L-4, where it can exchange war stories. Neither ever left the states, the L-4 spending it's wartime years at Ft. Polk, LA. I'm owner #7.
http://www.airport-data.com/aircraft/photo/023044.html