I don't have a definitive answer, but I know the P6s and original 225s have a model specific (and discontinued) slide catch lever. The 239s have their own specific one also. The 220 and 245 share one. And the 226/228/229s all share the same part which IS compatible with the 224 style lever. I do NOT know which one the 225-A1 uses.
FWIW, it's a simple and quick whittling job to shape a standard one into a reduced size like the 224. A little polishing and a bluing pen touch up and they look just like new.