search in nwexplorer has always failed for me. another thing I don't like is that all-caps files come before lower case. If you examine the very top of the list for the same texture pack, you will see a file in all caps which is what you are looking for. It's not down with the lower case ones. (Textures_Tpa)
In nwexplorer, the textures, I believe, are rendered in maximum resolution, so what you see is what you get. If it is larger than the view panel, the view panel resizes to compensate. So super tiny res images will look like flies on this huge monitor, and larger ones are reasonable quality.
One way to detect resolution is to screen capture and paste into something that can give you resolution details. Remember the images are in powers of two, so 32 64 128 256 etc., or down by 16 8, 4 etc. If you know how big on your screen a common icon of 32 pixels is, you can make a good guess at 64, 128, or 256. You know higher sizes will be an obvious 512 or 1024. For the purposes of your question, if the image shown in nwexplorer is the similar width as a desktop icon on windows, assume it's 32 pixels. Windows standard icon size is now 48, so it's close to true.
