Cleaning A 2nd Model Columbia Q Bedplate

[Jennison]

Forgive me if this has been addressed elsewhere; I couldn't find anything.  In the past, I followed the Compleat Talking Machine instructions  on cleaning a black japanned Q bed plate with dish soap.  That particular bed-plate was almost devoid of any original pin stripining or decals.  I recently acquired a really nice 2nd model Q with 95% of the bed-plate pin striping and decals still present, but it doesn't appear the machine has been cleaned at all.   How should I go about  cleaning the plate on this example?  My apologies for the lack of photos; I don't have the machine with me at the moment.

 

Thanks very much,  Jennison