You may contact Scott Riese. He does some great things with Tongue mufflers, I have seen some very creative solutions to interesting problems . reasonable rates as well

SRiese5283@aol.com
Tell Him Mark Scarborough sent ya

Hello Jim,

Joe Gilbert & I are assembling ARF Stregas for ST 60s.
These kits are really good, & got me to dig out my 60 size side exhaust shakers. I will use a late ST 60 engine with muffler lugs. I may interchange the early Merco 61 light case at some point. May even assemble another one for the Fox Eagle 60.(won't interchange).

While diging out the big boys, I found a couple ST 60s with a single ring but no lugs. I had forgotten that I had them. That was the reason for my post. I realy don't need these engines, but I thought that it would be easier to sell them with mufflers.
I beleive the ARF & ARC Strega kits will renew interest in the older 60 size side exhaust engines. 

The ARF Strega is impressive. My only complaint is my flaps are way too twisty. I will rebuild them.

Tom Martin