Help identifying mills

I got several mills in a bucket of drill bits at a yard sale this weekend. I'm hoping to get some help identifying them and determining if they are worth spending any time on. I don't have any way to use them, but will put in some time and effort if they can be sold. None are indexable, but all are through coolant versions. I think they might be manufactured by Kennametal, but I don't see anything with similar specs in catalogs or online. The largest has a 1" spindle and the cutting end is ~3/4". The others have a 3/4" spindle and probably 1/2" cutting end. All of these have two flutes and about 2.5" of cutting length. They all have a small amount of galling and fetching on the ends, but appear to generally be in decent shape. I have a few others that are in terrible condition like they were reground. Are they worth resharpening? I'm near Denver, and am looking for recommendations on a place anywhere in the US to send these to have them sharpened. I figure if a shop can resharpen them, I'd get more on the resale. Any information on manufacturer, name, etc would be much appreciated.

Also, what does 2xD or 3xD mean? I keep seeing this in catalogs, and can't decipher this.
Hopefully pics are attached.

Those are coolant through drills, look like they need some tlc.
3Xd means they are designed for 3 (times diameter) depth.
If you have a coolant through mill, they can be very useful.

But if you think those will make you a lot of money ,even if re-sharpened , think again! Likely the sharpening cost will be as much as you can get selling them. If you can even find a buyer. Now if YOU can use them ,that's another story.

Even if you have a lathe they can be used with some sort of adaptor to add coolant flow to the back side of them.

Most always if they were worth selling you would have paid much more. Often the best thing would be to touch them up or not and use then as part of a trade. First take what you can use and sharpen those up right. Running them dull will likely just burn them up quick.