Looks like the last guy was using a grease gun to lube the bowl bearings. There are a few different ways of lubing those bearings, Berkeley says to remove both plugs and squirt 90w gear oil in one till it flows out the other side and then replace the plugs. What you have to do is remove the square plug and pump some grease throught the zerk until you see clean grease come out the other side. The problem with this is the forcing of grease can put too much pressure on your bowl seal inside and blow it out, just go easy on it when greasing that zerk and you will be fine.
Mine is setup the same way and I'm in the process of rebuilding it due to that seal, among other things, being trashed.