Guido, If you look at the two pictures on Page 236, I get the impression that he is referring to both caps as #162 variants. Frankly, I'm a little confused with his description of the difference between the #162 and the #164.
I have the one with the diamond shapes in the cap but I've not been able to aquire one like the picture of Springerswimmer's with the slot shapes contiguous to the diamond shapes.
Again, after re-reading pages 236 & 237, I'm still a little unsure of the 162/164distinction . . . your interpretation may be correct.