Mike,
I have a "gifted-to-me" Jr. Flite Streak that I put a McCoy .19 on. The problem with an outboard tank is that there is not enough room for enough fuel. It runs beautifully for a couple of minutes using a standard vent medium wedge 1-1/8 oz tank and a 9" BY&O prop. But just about the time you have knocked off the dust and are really having fun, it is out of fuel. There is room for the slightly longer BH-472 tank and I'm sure that it would perform just as well, but the increased amount of fuel is negligible.
For reference, there is no tail weight on this plane. The cylinder centerline is about 2-7/8" ahead of the LE. I ran it without a muffler or spinner, and with the wood prop, so there is no extra weight forward. There is an extra 5 lbs or so in the "coat hanger" leadouts and goofy wingtip wheel unit, ancient silk and layered on dope. Actually, it is 19 oz. ready for fuel, warts and all.
If I recall correctly, I flew this on .012"x52' lines with no issues.
I have tried a deeper tank and the engine run quality goes away. And never came up with an inboard tank that easily fit. So it hangs on the wall. When picking your project, be sure to factor in the fuel quantity needed and the likely fuel tank size for the engine you are considering.
Last year, I refurbished a Magician .15 with all new covering. The original K&B epoxy paint on the fuselage was still in very good shape. But, it was a "nose wagger." The little Enya .15 shook so bad it wouldn't hold a setting. An old steelfin OS wasn't any good. The OS .15LA was only slightly better. An OS .10 might be the ticket, but I don't have one of those. An electric motor might be best, but (a) the likely size of the components retrofit to the thing didn't look appealing; and (b) I am not an electric kind of guy. Still, if you were to build a Magician from the get-go, you might be happy with the stiffness of the front end?
I have in work a 42-1/2" span, elliptical wing, full fuselage I-beamer that I call the SongBird. It is planned around a Veco .19 with stock muffler--and a bigger tank! Hopefully, I can get some other projects out of the way and get back on this one some day soon.
Have fun picking out your project!
Dave