So I really like this pattern and I saw a review of a very similar tank top version on patternreview.com:
New Look #6569
It has the same look, with the gathered front at the bust and a V-neckline. I wanted one... was going to purchase the pattern, but thought... well, hey... I have a similar pattern... let's see if we can make it into what I want. Here's what I turned out with.
The picture below shows the original sleeve piece and the finished tank top piece. I drew in the original lines for the front bodice so you can see where they overlap. Here's what I did.
Then I laid it over the raglan sleeve piece, matching the upper portion of the raglan sleeve seam and matching approximately where the armhole notches were, and traced the shoulder and neckline section. Then I just guesstimated the curve of the armhole.In this picture, I traced the front bodice piece on the finished tank top pattern. You can see where the original sleeve pattern piece overlaps the portion I added on for the tank strap. The seam at the top portion of the raglan sleeve and the shoulder seams match.
Here's the finished pattern front piece:
I did the same thing with the back pieces. Again, the picture below shows the finished tank top piece and the sleeve piece together, with the back bodice piece drawn in along the shoulder blade. The finished piece by itself is shown on the right.
That's pretty much it. The pattern is ready.
I kept the neckline binding the same and just finished the armhole by folding it over and sewing. Simple. Quick. And I have a TNT tank top pattern that cost me nothing more than a few minutes of my time.