There has been a lot of rework to this part of the left pane of plate 3, since the Neinken book. Much has not been published, unfortunately, and so its a bit difficult to provide a full clarification, but I'll list some of it courtesy of Deep Cert.
jaxom's 47-48L3 pair marked up:

A pair, 67-68L3, for reference:

First off, Neinken's mats for 47-48-49L3 have been moved up to actually be 27-28-29L3.
Here's a markup of the pair in question, with a few distinctive features noted with red arrows.
- Blur inside orns A/B of 47L3.
- Blur inside orn H of 47L3.
- Unusually weak orn Q1 of 47L3.
- Blur to right of left plume of 48L3.
- Candy cane off orn R of 48L3.
- Blur in orn Z of 48L3.
67-68L3 can be eliminated for this, since 67L3 has a crack in orn A.
The following stamp is believed to be 47L3, and it matches the left stamp in jaxom's pair:

The following two stamps are believed to be 48L3, and match the right stamp in jaxom's pair:

