I agree, if you are intimately aquainted with the sound of a given loco, and a model doesn't match that, then it will only serve to annoy.
I personally have recorded shays and climaxes for my Aussie logging tramway, and am fairly confident I could "recognize on by sound".
Ergo, when I heard the Soundtraxx Shay and Climax decoders, and worked out the only difference was the whistle, I was suitably "turned off".
(To take it furthur, I KNOW that Shay SN697, ex Nth Mt Lyell Tramway, now Lahey's Timber tramway, Canungra, QLD,
was equipped with a "locally sourced" bullroarer whistle,
and NO RTR sound decoders, even "shay" ones, will have that matching whistle. The Bachmann On30 shay visible matches SN697 pretty closely, but I haven't HEARD a model On30 shay represent SN697 yet!).
I'll refer to my earlier comments though, and say that you obviously have a keen ear for what "sounds right". There are therefore 2 possible options.
(Assuming you actually WANT sound,
if you don't, then the "what sounds right" debate is academic at best.
Forget installing any sound modules, and "Enjoy YOUR Trains"
1 - you find the closest commercial offering you can that "sounds right" to you, and live with the "not quite dead right" bits
2 - obtain a user-loadable decoder,
source the required sounds as deemed "correct" by your ears and recollection,
and "scratchbuild your own".
Seriously, this is no different to scratchbuilding a loco or car, because the <Insert fave prototype> version is not available RTR!
You can "R.T.R." sound,
(buy a decoder or ITTC model,
install, and enjoy),
(download a copy of Audacity, and some "prefab" sounds from somewhere,
tweak as required,
and load into Loksound decoder, CD/MP3 player, or DreamPlayer),
or go the whole hog and "Scratchbuild" sound
(start waaaay back with whatever recordings of the "Real thing" you can find,
use them as reference material just like you would with photos for "visual scratchbuilding",
clean them up or recreate them with synthesis tools,
and then load into decoders or playback modules)
The option is yours,
the "level of effort" is up to you,
(some people enjoy handlaying track,
some prefer PECO,
as long as both modellers are Enjoying Their Trains,
it matters not 1 iota which option they choose...)
but if you are using a "Hyper Specific" benchmark,
be prepared to put in some work to achieve it!