'97 75 hp Merc trim/tilt relief port??? plug???

This year in my rush to get the boat in the water I forgot to put the battery back in and raise the motor before I pulled it out of the spot I had it stored. My tires had gone flat on the trailer over the winter so when I pulled it out I ended up dragging the foot over a mound, probably hit it pretty hard. When I got it outta the bush I looked at things at the back and saw some oil weeping from the very bottom of the trim pump. <br /><br />I ended up putting the battery in and tried trimming the motor up and ended up pumping the oil out onto the ground from this pump. I've looked it over pretty well and the oil is coming from a port right at the bottom of the manifold located below the pump. This is a yellow fill plug single cylinder system which can be seen on Merc's parts express website under power trim stuff for serial number 0G301751. Unfortunately Merc's parts breakdown doesn't show anything on the externals/internals of the manifold where this oil is coming from. <br /><br />After pulling things apart abit I can see the same type of port on the other side of the manifold which I assume is to be used as a relief. From looking at the other side it appears this port is plugged with a rubber coated steal ball of some sort. I expect that this is intended to relieve if there is a significant over pressure caused by hitting a rock or doing something like I did. <br /><br />I expect if I was to locate a replacement ball I could simply pop it in there refill the system and get the boat in the water, unfortunately I can't find any reference anywhere to this port or ball or anything. I went to my local merc shop and the guy listened to me for about 20 seconds and said bring it in and he'll look at it. From my history with this place I expect if I brought it in and all they did was replace the ball it would still cost me $200+. <br /><br /> Has anybody dealt with the same thing? Anybody know if I'm off base here? Anybody know where I can get a part number or description and source for the ball? <br /><br />I'm going to be out of town this weekend and hope to stop by a different Merc shop and see if they can give me a little more attention. Failing that and if nobody here has any good ideas, I intend on drilling and tapping this port then just using a machine screw as a plug. I'll remember to lift the motor next time though.