I'm going from memory here so please be patient with me. I normally post over at the hosta forum and I know nothing about geraniums. In fact I didn't know the plant in question was a geranium until my aunt gave me a division of hers which looks like Brookside. My geranium looks similar to the one I'm interested in IDing but something is just a little off about it.
About 50-60 years ago my grandfather planted a geranium/cranesbill that I just loved but the plant has since died. I grew up with the plant, my grandparents sold the farm to my parents, and I've been trying to discover what it was ever since.
It was a very hardy plant that formed a tight mound 18-24" high and about 36" across. The foliage seems typical of what I've seen with the leaves having little "fingers" instead of being all one piece. The flowers were a rich bluey-purple with distinct darker veining and I think yellow stamens/anthers/reproductive bits at the centre. They were cupped and grew on medium length stalks, the flowers were at most 6" above the foliage. I remember something about the plant was very soft and fuzzy. I am reminded of the texture every time I touch that fake suede/microfibre stuff.
I really appreciate any help you can give me. If you need more info I will see if I can dredge anything up from my parents memories.
The fuzzy leaf texture, if you're remembering it correctly, would suggest maybe G. renardii, however, it has white flowers with blue veins. One of its hybrids, 'Philippe Vapelle', has blue, veined flowers - could that be it?
