According to Dr. Friday, none of it is Kashima Shin Ryu, as Paul Smith's "Kashima Shin Ryu" comes from Inaba Minoru.
That doesn't mean it's bad or worthless, just that it's not actually Kashima Shin Ryu and should be called something else.
KSR diehards will always say that and I guess it is true. But, if I practise Judo kata in my Aikido class should I tell them it's Judo, or should I call it Aikido? But given the way Aikido styles differ, I guess KSR diehards must quivver some when they see how it gets altered when done in other contexts (like Aikido).
Anyway, when I was doing Shiseikan I think some of the seniors were training separately in KSR alongside Aikido, though I am not sure. In Japan, these days, more than a few Aikido sensei are studying traditional ryu of one sort or another to compliment their Aikido. Usually though, they are not allowed to teach it. I remember that Igarashi Sensei came to Korea every year to teach Aikido when I was there. Everyone thought he was also teaching Katori Shinto Ryu - since he also did that - but in fact at first it was Saito's weapons (not that they'd know it) and later on it was his own new system he taught. No wonder everyone gets mixed up. Just as I was leaving Korea I heard that a genuine Katori Shinto Ryu Sensei was arriving to teach for one year - so I guess I missed out on that.