Luckily, I am in the middle of rebuilding a '28 engine, so today I took a couple of pictures of the cam gear area.
The first photo below shows the cam gear area. Notice the curved sheet metal scoop in between the gears. This cup catches extra oil that is slung around the gears and allows the oil to return to the block.
The second photo shows inside the block behind the area shown in photo one. The hole that is circled in red is the where the extra slung oil flows from the cam gear area back into the block.
Yes, you can reach this hole from under the engine with the oil pan taken off.
That being said, the oil catcher cup is about two inches above the bottom of the cam gear box. There is no oil drain hole at the bottom of the cam gear box.
Oil WILL build up around the crank cam gear. If the cam gear cover has a leak, it's gonna leak.