Werra, if you just need to mount it to a lensboard, if it's a standard #3 and not an 3S variant, the thread is a standard for fliter threads (62mm?) If I remember, a 67-62 step down ring with either a couple of small holes or two slots filed into it will allow you to mount the shutter as long as you don't have to reach really deep (e.g. wood lensboard without a rabbet)