I sold off my last two Martinis...a MK-2 and 4. I had installed a 12" rail on the MK-2  the unertl bases were way out there! I used those screw holes to mount this rail and then mover the Unertl bases back against the breech.Works very well. Had guys PM me on where to get the rail. A buddy went to Brownells and searched em out for me,no longer in catalog. I bought two more for other projects. so heres the number 080-031-841    no 840-12  dove tail scope base stock.  $34.00 for two shipped. Pete