I agree with what Mark & KP have written. I'm afraid by the time you've spent a dollar for the efforts of making new prod.HM300 paragraphs look like original "no.no" exhaust, you'll have saved a little more than a dime. It's difficult to answer "what's it worth" fitting this exh.set or that exh.set, given bike valuations are subjective and market is fickle (at least for now.) Perhaps, the question is, what do you plan to do with the bike? If riding it on even a somewhat regular basis is planned, it's going get road wear. In that case (for me) the common sense thing would be to put on a set of new production oem HM300 paragraphs and be done with it. They're relatively inexpensive, they look great, sound original. If you're going for a no holds barred perfectly correct restoration, then (for me) Yamiya's are the only choice. At this moment, Lotus Roots are not available, so unless another group of members get together to propose to Yamiya another LR prod.run, getting a set of LR's is not an option. Not sure "I" would want to spend $2k+ on a set of "no.no" last type Yamiya's, given they are not the exh.type used on your bike, although, one would then have a lovely like original set of unstamped exhaust that externally appear like original except for a taller welded seam.
Has anyone bought a set of the Vitnamese exhaust ? I don't recall hearing any member reports of fit and appearance. The pictures of exhaust in the Vietnamese ads, the chrome looks more shiny over all of the muffler than original.
I think i said, in the case of my 2157, because i am not restoring it and plan to use it as a rider, i opted for HM300 paragraphs. For me, it was a practical choice.
Having your Georgia plater fill in the paragraphs and rechrome the set for $400, seems not an objectionable price for the modification, if that option can make sense for you. Have him fill in the HM300 while he's at it and see if he can weld a plate over the #4 relief for a few more bucks, you're still under the $2k+ price for the "no.no" Yamiya's. The 6mm hex screw holding the baffle is welded in, so not twisting off the screw to remove the baffle is the trick.
You said your brain hurts from all the thinking. The diagnosis for these symptoms is sandcast fever.
PS - There are no import duties or fees for goods shipped from Japan to USA.