It is slightly angled at the periphery but no it is not a stepped dial. Here are pics of 2 similar looking straight lug Speedmasters. The first is a 1960s Ed White, the second a current FOIS. It is tricky to see but there is a definite step stamped into the EW which is not present on the FOIS (or Pro model from ~1974 to 2020). The new reissued Ed White, or more correctly named 321 Speedmaster has a step as does the newly introduced Pro model. Several other models have had stepped dials over the years too.
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View attachment 1187941
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