I recently came across a Leica M4. I know next to nothing about these cameras, other than remembering from my childhood that they are of high quality. Full camera markings are Leica DBP, M4-1229775, ERNST LEITZ GMBH, WETZLAR GERMANY. Lens range is 28"- 25', or 0.7-10 meters. Any info anyone has about the quality and /or value of this piece would be greatly appreciated!