Glad to see there is another source for the smaller OS engines! Thanks!
A friend bought one of Scott's tongue mufflers for an OS 15LA. BEAUTIFUL piece of work! Ran really great, too.
I have no experience of Brodak's product, but he does try to offer the best he can - should be good.
I have (aluminum) brazed my own mufflers for decades, but bought available market items when they looked good. Results, both ways, invariably good.
I would never offer to build a chip or 'standard' muffler for anyone else - too much work, and too high a chance of needing to scrap a partially completed piece for a bad start...
BTW, the "mufflers" provided with the NorVel .049 and .061 or AP .061 cu in engines do very well as stock, and many provide a nipple to tap muffler pressure to augment fuel draw. The mufflers on the AP .09 and .15 engines too - and they DO knock down a lot of noise as well.
Of course, small diesel engines only sound loud at hands-on distances - their 'loudness' fades rapidly with distance. If your flying field requires mufflers, regardless of loudness standards, you are at a slight disadvantage.
OR - you could do as a guy in Massachusetts did in the 1970's... He had devised an electric-powered bicycle motor-pack. State (er, Commonwealth) law required ALL motor vehicles to be equipped with an 'approved muffler,' He found an inexpensive 'approved' lawn mower muffler and wired it onto the electric motor. We were there, then, and had to laugh, unless we chose to cry....
Hmmm... does the mandatory muffler field requirement apply to electric-motor powered models?