Grade Master3 cartridge--Moving Iron Design

Pickering is listed in the legend to your figure after point #2, as an example of "moving magnet". As I am sure you know, Pickering and Stanton were associated with each other. Most models of Pickering have a corresponding model among Stanton cartridges.  Both companies marketed a low output MM, the Stanton 980LZS (also the 981 variant) and the Pickering XVS7500. These have a much lower inductance and internal R than do the typical high output MMs from anywhere. It IS interesting so see illustrated the differences among MI, variable reluctance, and induced magnet (IM) types.  We usually don't bother to make a distinction among types 3, 4, and 5. For example, in this thread several refer to Decca as MI.

Pickering and Stanton are MM, so far as I know. All of them.

Peter L started out, I think, repairing B&O cartridges, which are all MI types, and the best of them can compete with any modern cartridge, IMO. That, I am guessing is how he got into the MI business. Even now he makes the SMMC line which is a reprise of the old B&O cartridges.  Unfortunately, it does not appear that he can get the hollow sapphire tubular cantilevers of the old B&O MMC and MMC20CL series. That cantilever may be a key to the fantastic sonics of yore. I love MI cartridges and have yet to hear a bad one. All of mine are high output types.