My bow.

Pretty similar to Kane's Aabow, except for the money maker, or the plunger head. I used a skirt seal, the same one used on the Plusbow plunger tube (1.375" ID). 1 1/4" PVC happens to be 1.362", or the stuff that I got is. I apologize I don't have pictures for this, but it was done a while ago. The plunger rod is 1/2" hollow aluminum tube. To secure the skirt, I lathed down a piece of wood to fit over the aluminum tube and also fit inside the skirt. FYI, the ID of the skirt is .875". The front of the piece was also flared out to prevent the skirt from falling off the plunger rod while priming. To prevent it from moving backward while firing, I just filled the void between the plunger rod and the back of the skirt seal with duct tape. I may eventually replace this part with something better, but it's working fine for now.
Add a little silicone grease, and you have a perfect seal.
Now some of you are probably thinking that funnel is going to get in the way of the bow arms, and string. It actually doesn't. I cocked my hopper clip enough to the right so it doesn't interfere. But then, my hopper clip, with all the weight, should fall over while I'm jostling around. Tightening rings is how you fix that.

I took a pair of brass cutters, and slightly raised the OD of the PVC. It creates a nice tight fit between the wye, and whatever you're plugging it into. I recommend doing this to every piece of your hopper clip assemblage. It's A LOT better than gluing stuff together and/or to your gun.