Chris, 
This is the thing that I desperately want our hobby to differ from than others where restoration is concerned.  As a member of the classic and muscle car hobby as well, I feel that FAR too much emphasis is placed on whether this part was painted or plated, inspection marks, etc. etc.
Antique Tractors have for a long while now been an area where those nit picky details can be somewhat overlooked, and the concept realized that indeed the same job might not have been done the same way from day to day, or tractor to tractor for that matter!  Thank you for saying this.
One of my fears of people restoring these tractors is that there wont be enough of the good originals left to use as reference guides.  Which is why we dont paint our one or two owner tractors. <!-- s:wink: --><img src="{SMILIES_PATH}/icon_wink.gif" alt=":wink:" title="Wink" /><!-- s:wink: --> 
The automotive collector groups have finally started to realize this and have made categories for these that they call "Survivors"