A Nelson's Sharp-tailed Sparrow?

Better Birders than Me (that would be most birders)—I could really use your help!  

I’m attaching a few photos of what I think might be a Nelson’s Sharp-tailed Sparrow.  I’d really appreciate confirmation OR your thoughts on the correct identification of it being a different sparrow.

I’m including photos with NO touch-up of any kind.  I simply converted from RAW to JPEG, cropped, and saved.  The photos are not good, but I’m hoping “good enough” for identification.

The Habitat:

I know that “Sharpies” are found “almost exclusively in grassy marshes”.  I’ve spent a few years participating in the Freeport CBC, and after one December’s cold dawn of slopping through thick, pristine, waist-high marsh grass, (supporting the team lead who was specifically searching for a Sharpy), I never did that particular hunt again.  My knee-high rubber boots could not be seen in the marsh thickness; and the dawn wetness left me soaked up to my waist.  It was a miserable-cold morning and my jeans never did dry.  I was just thankful to not have been snake bit!  I was disappointed at not sighting a Nelson’s Sharp-tailed and with that experience, I pretty much gave up hope of ever adding the Sharpy to my lifelist.

But yesterday found me birding one of my favorite spots:  the marsh side of Galveston Island State Park.  I’d donned my rubber boots and was slowly walking the sandy, mucky, grassy, brushy, marsh-side of the park.  I was delighted with what I was seeing in the way of the expected.  Suddenly I sighted a sparrow flush out of marsh grasses, and into the brush.

Here are the two close-cropped photos.  The breast, belly, bill-color (same as cheeks), crown, and lack of wing barring caught my eye:

And here is a pull-back photo of that habitat (unknown sparrow top center):

And I’m including this Reddish Egret photo to show you the habitat just to the left of this brushy area (many more Reddish Egret photos on an upcoming post!):

This bay water goes behind the above brush-sparrow photos.

As a side note:  this time-of-the-year is that miraculous intertwining of summer and winter coastal birds.  Towards the end of my day-trip, I was watching Scissor-tailed Flycatchers (summer bird) along the power lines of GISP, when a loose flock of Palm Warblers (winter bird) came through.  I’ll share the Palm Warbler photos soon. 

But for now?  Another beautiful day in Ahhctober—and another day trip!

What do you think?  Can I claim a new lifer?