I would like to install Davidson bases on my 40XR BR Rimfire since I don't like the one piece Leupold base that is on it now. I ordered a set from Sinclairs that said was for 40X actions. It came but the screw holes do not match the gun . The rear base is correct but the front holes in the base are about .620 and on the gun the spacing is about .908. Does anyone know where to get correct bases for my gun which was mfg in the 90's.