Currently:

Chet Slomka (18/68)
Chester L. Slomka (20/55)
Chester Slomka (36/69)

If all the Absence of Malice, Ladyhawke & Outland are fixed and he is removed from the 18 profiles for Close Encounters of the Third Kind for which he was credited only as a Sound Effects Editor Chester L. would be the most common form.

Chet Slomka (??/50)
Chester L. Slomka (??/84)
Chester Slomka (??/37)

There are a lot of Sneakers and Black Rain profiles on the latter two forms that could sway things (see note below).  I don't own them but the AMPAS website (go there and search for his last name) indicates Chester L. is used on most titles.

http://ftvdb.bfi.org.uk/sift/individual/465441?view=credit
http://www.imdb.com/name/nm0806153/

Note: Profile numbers updated based on 8BallMax's confirmation of Sneakers and Black Rain.    Titles are a bear to parse/count but given there are no movies with excessive profiles to skew them i believe they will track with the profiles.

Thanks, that swings things pretty strongly towards Chester L.  I've updated the numbers accordingly.

Noted.  As soon as Ken has a way to link all the title variants i'll be happy to use just titles also. 

I don't think there are any titles with an excessively large number of profiles for this guy so i believe the titles count will follow the profile count.