PART NO.  SPL.PAGE  DESCRIPTION                                                           
17H932    15.O.2    Nut -knurled -small (2 for speedometer strap)
17H932    15.O.2    Nut -knurled -small (2 for revoution counter strap)
17H932    15.O.3    Nut -knurled -small (2 for oil and temperature gauge strap)
17H932    15.O.3    Nut -knurled (1 for fuel gauge strap)
17H932    16.O.1    Nut -knurled -small (2) -(oil pressure and temperature, instruments, 
    1600 and 1600-MK-II)
17H932    TC.O.1    Nut -knurled -small (2) -(speedometer, instruments, Twin Cam)
17H932    TC.O.2    Nut -knurled -small (2) -(strap, oil and temperature gauge, instruments,
    Twin Cam)
17H932    TC.O.2    Nut -knurled -small -(fuel gauge, instruments, Twin Cam)
17H1304   TC.O.1    Nut (knurled -large) (2) -(strap, revolution counter, instruments, Twin 
    Cam)

These are the knurled nuts for brackets securing dash instruments to the dash panel. Two sizes, large and small. The female thread is 3BA for all. I believe it was intended early on for the small nuts to be used on the smaller instruments, fuel gauge and safety gauge, while the larger nuts would be used on the larger instruments, speedometer and rev counter. the SPL's may have errors for where the different sizes were used. 1500 and Twin Cam call for the larger nuts tto be used for the rev counter only. 1600 calls for the smaller nuts to be used for all instruments. Moss Motors USA seems to confuse large and small part numbers depending on which application is listed. They are in any case physically interchangeable. I would recommend using the larger nuts for all applications, as the larger ones are easier to handle and to tighten with your finger tips.

Alternate part numbers:
BMC = 17H932 (small)
BMC = 17H1304 (large)
Moss Motors USA = 360-370
Moss Motors USA = 361-035
Scarborough Faire = SS67N (large)
Scarborough Faire = SS68N (small)