My hunch is that it'd be a tad too small, but wanted to add one more comment before you give up: You mentioned wanting to wait for a 60cm, but there actually wasn't such a thing in this era Atlantis. Even though they came in the normal-for-the-time 2 cm increments, there was an odd 3 cm jump between this one (58) and the next one (61). Standover and some other dimensions took an odd turn at that increment. You should fig up the old geometry charts from Jim's Cyclofied website to make sure it would work - or that this one wouldn't (assuming you have your heart set on this vintage.)
I remember this all too well, because I wanted one so badly, stared at the charts forever, and tried to rationalize buying one even though I fell squarely between sizes. I was convinced it was some sort of conspiracy by Grant, that started with the missing size 57 cm XO-1 years earlier. I never got the Atlantis, but did end up with a 60 Ram, a 60 quickbeam, a 60 Saluki and 60 All Rounder... because I couldn't have "the one." They all fit me great, but the Atlantis just wouldn't have. (FWIW, I'm 6'-1 1/2" and have an 87 PBH. All torso)