I don't know crap about PLSS surveying; however, our town was surveyed in 1850 with 35 blocks and a square. No lots, just blocks. At some point, no one really knows when, there were lots that magically appeared and they sold the North 10' of Lot 1, et cetera. So, I feel you on the "it ain't called for" bit.
What we do is we call the tract out of the block, and then say it is sometimes called Lot 1, but not on the recorded plat. I'm sure at some point, someone gave it a number and folks are using that. Don't make life more difficult, just call it what it really is, and then explain what it's "other" names are so the chain of title works.
Or at least that seems to work around here.
1855 Manual
Loyal & Jerry:
The Diagram B in my C.A. White's book (PDF and not a printed copy) is not really any better than what is in the compilation book that I posted the excerpt from the 1855 Manual. It does show some lots as numbered and some not numbered though. Anyway I am including what I did print and scan.
1855 Manual
Figure B is also reproduced in Dodds, Original Instructions Governing Public Land Surveys of Iowa, foldout facing p. 144. It is better than in the printed White book, but still barely clear enough to confirm what the wording indicates along the northern or western sides of the township. I can't make out lot numbers in section 6, though, where an example would be most important.
1855 Manual
There also is a diagram in the "Manual of United States Surveying by J.H. Hawes at page 118 that is pretty clear and is somewhat similar to the 1855 Diagram B, but is not identical in all respects. This seems to be in the 1860's time period.
I did manage to make out a few lot numbers in some of the Western tier of sections on the 1855 Diagram B. It also appears that this Diagram has two systems of numbering of the lots. The older version and newer method in the Northern tier of sections.
I have an Original 1855 Manual. I will look at Diagram B at Section 6 and see if the lots are all numbered later today. It is too big for me to scan.
Section 6
The South half of the Northeast Quarter is No 1
The North half of the Northeast Quarter is No 2
The entire South half of the Northwest Quarter is No 1
The entire North half of the Northwest Quarter is No 2
The East half of the Southwest Quarter is No 1
The entire West half of the Southwest Quarter is No 2