Within a couple of days I could stand, even make two, three steps.
It is the original sentence. And I have a strong belief that the and is deleted as below.
Within a couple of days I could stand, (and) even make two, three steps.
"And" is deleted, but I do not know why that is possible. This seems to be a very unusual situation to me, because if "even" was not there, this sentence would just sound off to my ear. What's more, "stand" and "make" are two verbs, not adjectives. So what rule or usage makes it possible to delete "and"?