Hi sv2023.
I would think that, after a month, your GMAT verbal skills will be about the same as they were before that month. Sure, you may be slightly rusty, but with some mixed question practice and a review of some key concepts, you should quickly get back to where you were.
Accordingly, you best move is likely to do some mixed practice and analyze your
error log, practice tests, and your performance on verbal practice questions to determine what you need to work on in verbal to increase your verbal score.
That said, if you just want to maintain your current score, mixed practice would reveal what you need to review to get back up to speed.
Maybe you could clarify for us whether your goal is to score V40 or to continue to increase your verbal score.