Some say TTS; some say size it like the Barrie (this thread has discussed this issue before, as I recall; there is no right or wrong).
I am TTS 9.5D.
My contact at the Alden factory tells me the M-58 and the Barrie should be sized the same. In my experience the M-58 is slightly shorter (I went to a 9.5C in M-58 from my usual Barrie size of 9D). However, I also have Barrie in 9.5C. Generally speaking, a 9.5D in Barrie and a 9.5D in M-58 are slightly too large for me. In my experience, a 9.5D in either the Barrie or M-58 (both of which I have tried on, or owned) is noticeably larger than other Alden 9.5D's.
Conclusion: try on a few sizes if you are able, IMO.