For your situation, you need to be sure of a number of things:
Do your gutters over-flow in a rainstorm? Do they slant towards the downspout(s) so water can run out of the gutter? Are your downspouts free and clear of obstructions? Are your downspouts exteneded at least 3' from the foundation? (More is better ...) Is the landscape around your foundation sloping at least 1/4" per foot for a minimum of 3'? (ie., positive sloping) Is water from the surrounding property(s) running onto your lot? (If it's a natural flow, it's OK. If they did something to the lot that ALTERED the natural flow, and it runs on your lot, you MAY have a valid complaint.) Are you missing any gutters/downspouts? Does water pool on your lot?
What you can do is walk around the property in the next heavy or steady rainstorm. (Put on some boots and carry an umbrella.) Do look up at your gutters and look where the water is running when it comes out the downspout. Depending on what you see will dictate what you need to do to 'fix' your seepage problem. 90% of the water problems on a lot are attributable to the issues I raised. This should keep you busy for now. There really isn't anything you can do to the foundation to keep the water out. I don't think you want to dig up the foundation around the house to install a french drain or a tile drain because it may collapse. A 90 year old house on river stone is solid but it will 'move' if the earth around it is sufficiently disturbed. If it comes to this, talk to a pro first.
If you have more questions on this, e-mail me directly. My best to ya and hope this helps.