I recommend you find the right size from the OTR selection then from there, make the adjustments on your MTO. The adjustments are actually very limited so you'll be keeping most of the S&M signature shape/style. If you don't find anything that works OTR, then I highly doubt you'll be able to make something custom that fits 10/10.For those who've ordered MTO sport coats...
Did you send in a well-fitting sport coat you already owned so Spier could nail the measurements or did you enter the measurements online yourself Measurements are easy enough to do on a shirt but I'm apprehensive about it with a sport coat, especially when it comes to the shoulders.
I've thrifted so many vintage Ivy/natural shoulder sport coats over the years and despite the measurements being on point for whatever reason the shoulders didn't sit quite right (I'm probably batting below the Mendonza line when it comes eBay over the last 15 years; I return far more than I keep). Armhole height? Maybe a sliver of padding that screwed up things? I often find when the shoulders fit perfectly it's too tight across the back. If I have ample room across the back, the shoulders are a little too big. I have two 1960s Brooks Brothers tweed sport coats that fit absolutely perfectly outside of the body being a bit short. The remaining ten or so sport coats in my closet don't fit as well as I'd like. The last thing I want is to go through the MTO process and find the shoulders don't fit/sit perfectly.
I have asked my tailor if he'd measure me but he refuses to do that for his customers; he used to and some folks would come back to him and want him to cover the cost for redoing an MTO job based on his measurements that didn't workout from another provider. Can't fault him for that decision.
@spiermackay Rick, do a lot of your customers who aren't local send you sport coats for measurements? I know you offer (or least used to) a one-time do-over for new custom shirt customers but obviously the cost to redo a sport coat is significantly higher.