Well, that only took 2 minutes: I searched and found exactly what I was looking for in Metalmorphous' thread devoted to the construction of his Ziroli P-38.
http://www.rcuniverse.com/forum/fb.asp?m=7837699
Perfect, now just have to go out and collect the materials.
Some photos of the 50 cal results this weekend (assuming I can find both the materials and the time).
Noah