I just bought a home in CT. that's about 70 years old. The foundation is field stone with cinder blocks on top which leads us to believe it's a second structure. We've also got an exterior foundation which looks to have been a porch or sun room. I spent countless hours last winter with trovel in hand, I spred 700 pounds of mortar mix filling in my holes, I had the same prioblems during heavy rain also. We re did all our gutters and ran the downspouts to 4" solid PVC which ran to a small dry well. This seemed to have really helped as the basement is not nearly as moist this spring. I've heard of some sort of blown insulation/sealer but I think that if your gaps are as big and deep as mine(some 8-10") the best thing to do is set up forms and have hydrolic mortar or cement pumped uin. I have one wall that's 20' long or so in horrible shape and it would take twice as much time & product to fill those gaps. I guess I should start them though unless I hit lotto (Inever play) because masons in this part of the state would make 300 a day to hand fill my holes! GOOD LUCK!