Tony:
You're absolutely correct; it is the pipes! I took a closer look at the manifolds and because the right side bolting surface is on a plane parallel to the ground and the left side's plane is canted to the outside, I thought that they needed to be reversed. This is, until I realized that the the left side had to be canted out in order to bypass the starter.
The first picture below is one of the bottom of my engine with the front facing to the left in the picture. The manifolds on it are the same as those in the first eBay listing you gave me. (Thanks, by the way, for that reference!)
However, the pipes available from Mac's and elsewhere will have to be modified. The first or what would be that commonly installed on the right side has a fork in it which would need to be cut off and moved to the other side of it in order for it to be installed on the left side of the engine. See the second picture.
As for the pipe that now needs to be moved front the left side to the right side, it will need to be bent to meet the end of the newly moved fork on the pipe now attached to the left side. See the third picture. (Although I copied the pictures of these pipes right out of the Mac's on-line catalog, the one in the third picture doesn't look like it's bent correctly to be installed to meet the fork!?! Do I have the correct piece shown here?)
The directions I laid out in the previous two paragraphs are only my best guess as to how to "fix" the pipes. Please let me know if I'm on the right track.
Best regards,
Jim