185 Sullair leaking oil around filter??

Hey everybody, new to the site, not sure where to post my first question, feel free to move if necessary. I have a 1979 185 Sullair compressor hooked to a John Deere diesel on my sandblast rig. I'm having an issue with the oil filter for the compressor. With a new filter, I have no leaks or issues, But after about 4 weeks it begins to drip on startup from around the seal. Then it will stop after reaching normal temp. After about 6 weeks it will get to just running out all over the place on startup but will still seal closed after reaching a higher temp in a matter of minutes. I have a Baldwin filter on it, and have tried a couple other brands, although i would prefer a real Sullair filter, but 3 times I ordered one it didn't fit. I'm not too sure that the issue would be the filter brand anyways, I have never seen this before. The seal looks to be in great shape, and the seat is flawless. Could there be a difference in the filters and it actually be the filter brand, or is this an issue with the compressor itself? thanks

185 Sullair leaking oil around filter??