Had same issue as you with my Seidel 770. Made a long "J" shaped tube from K&S 1/16" brass tubing. Soldered a short piece of the next size down brass tube to the short end to form a nozzle and soldered a flat piece of brass to the bottom of the "J" to allow the piece to be bolted in position to the firewall. The long side of the "J" comes out to the front of the engine between a pair of cylinders. If you baffle the engine (which you should), the tube can pass through a grommeted hole in the baffling which provides good support for the long end of the tube. A squeeze bulb with some fuel tubing makes it easy to inject the prime. I cap the long end of the tubing with black rubber cap I found at an automotive store (brake line cap???). With the black cap, painted black brass tubing, and black baffling, the fitting really isn't visible except with close inspection. I'd post a pic but I'm in the middle of a house move so everything is in storage.