shape doesn’t tell the whole story, do you mean someone looked at her size and assumed a MW? That is more reasonable, BUT, MW in what saddle? There’s no standard for saddle widths at all, so a MW in Brand A could be equivalent to a W or M in Brand B. There’s just so much variation on how a brand decides on width, whether they call it a M, or 32cm.
Yes to the Amerigo Vega! I was trying to remember that name earlier but couldn’t pull it out of my heat. My TB mare is built similarly to yours in terms of wither height and length, hollows beside the withers, and the bit of curve to her back. BUT, she also has wider shoulders than just looking at her suggests. The Vega was a phemomal fit for her. I didn’t end up getting it for her because the tack shop (who was the fitter, a very good one) didn’t have it in MY size, and a new one was $$$$, and I ended up getting a used County dressage saddle for her.
BUT, the County CC saddles we tried that day didn’t fit her terribly well, which is why I didn’t mention them earlier.
Prestige is another brand to consider, as Prestige also fits my mare well. Taller pommels, some curve to the rear panels.
What size seat are you looking at? Someone needing a bigger seat can run into problems with the last rib, which is why looking for upswept panels gets important.