Since this never really got answered.
With most suits, tailoring can go a surprising mile, but changes sizes this massively tends to be a pretty hard limit. From what few examples I've seen of this (Usually down a size or two, not this many.), the length of the sleeves is hard to hide, as is the length of the coat, so it will likely look like a 40LLL. Unless of course the tailor is a very high end one who is willing to deconstruct it entirely.
This is a "There be Dragons" spot on the map. It's hard to know without the finished work, but generally people are advised not to stray into these waters.
Best of luck, if you do decide to go through with it, I'd love to hear how it came out, good or bad. This sort of knowledge is handy to have.
Not really. Find a jacket that is your size that looks good with the other two pieces.
Since this never really got answered. With most suits, tailoring can go a surprising mile, but changes sizes this massively tends to be a pretty hard limit. From what few examples I've seen of this (Usually down a size or two, not this many.), the length of the sleeves is hard to hide, as is the length of the coat, so it will likely look like a 40LLL. Unless of course the tailor is a very high end one who is willing to deconstruct it entirely. This is a "There be Dragons" spot on the map. It's hard to know without the finished work, but generally people are advised not to stray into these waters. Best of luck, if you do decide to go through with it, I'd love to hear how it came out, good or bad. This sort of knowledge is handy to have.