Here is my 5018, in stainless steel, an "under-the-radar" favorite of mine that gets a lot of wrist time. This example is from the 1950s. This lug style continued to be produced in limited numbers into the 1960s and possibly later. If you have any examples, please share!
Holy moly! Clean, clean, clean, and red "Officially" to boot! 🥰
I don't think I have ever seen a 6090 in stainless steel. Only gold. What is the difference between a 5018 and 6090? Why do you call it a non-bubbleback?