Automator Workflow Copying Files

I'm an amateur photographer who takes ~300 outdoor portrait pictures in each set a few times a week. When I do, I shoot in both raw and jpg. I use jpg so I can open all the images when I return home and quickly go through to delete the 50+% of them that don't make the first round of cuts. I open all the jpg images in Preview and Command-Delete the poor-quality photos quickly. I use jpg in conjunction with Preview because I can open all 300+ of them within about 3 seconds (as opposed to opening all 300 in raw, which sometimes takes very long). In addition to the initial load-time, many times I need individual pictures to load quickly (less than a second) as I scroll through them so that I can quickly and more easily determine the difference between two similar photos. When I delete in Preview, the jpg files also move from finder to the trash. So far so good.

Once I've got it narrowed down to the 30-40% of photos I want to work with, I go to finder, sort by name, and delete the raw files that don't have the same file name (with the jpg file extension) by hand. Much time is spent doing this several times a week.

Below is a short example of what Finder looks like just after I delete my first batch.

DSC_1107.JPG

DSC_1107.NEF

DSC_1108.NEF

DSC_1109.NEF

DSC_1110.JPG

DSC_1110.NEF

DSC_1111.NEF

DSC_1112.NEF

DSC_1113.NEF

DSC_1114.NEF

DSC_1115.JPG

DSC_1115.NEF

DSC_1116.NEF

DSC_1117.JPG

DSC_1117.NEF

DSC_1118.NEF

DSC_1119.NEF

DSC_1120.NEF

DSC_1121.JPG

DSC_1121.NEF

DSC_1122.JPG

DSC_1122.NEF

DSC_1123.NEF

...

Once I reach this step in the process, I'd like to use Automator to do the following:

Delete all NEF (raw) file extensions that do NOT have the same file name in conjunction with the jpg file extension.

I would appreciate a walk-through as to how to handle this.

OS X 10.10 (Yosemite)

MacBook Pro (Retina, 13-inch, Late 2013)

2.8 GHz Intel Core i7

16 GB 1600MHz DDR3

Automator