Was there an upgrade available to go from oil bath to dry filter element using the oil bath housing? I bought the oil and parts solvent to service the oil bath air cleaner today, and when i pulled the bottom off low and behold there was no inner cup and the filter was a paper element. i am sure it was originally an oil bath as the stickers are still on the housing that says it is an oil washed air filter. also, there was a little oil in the bottom of the filter housing. is that normal? not enough that it pooled up or ran out or anything, but enough that i got my hands covered in dirty engine oil.