The reverse looks normal. I googled "no date wheat penny" and found there were others like it and like here everyone believes it was altered. If it was a old alteration say 50 years ago and the patina now looks natural, what would be the reason? Was there value for a no date penny back then? If you click on it and zoom in you find no scratches other then the two that really are not in the date area. Could there have been a test run in 1909? I found one on EBay similar. With all the other post on different sites about a no date wheat penny someone was busy scratching all the dates off, lol. I don't believe I could do such a alteration to where it could not be detected under magnification.
First of all, let me share a small bit of my life. At 8 1/2 years old I started sweeping metal shavings out of the way in my dad's shop. By 10, he could hand me a blueprint, pick out the metal and leave me to make the parts. Since that time I have worked in high-tech and close-tolerance jobs mostly dealing with metals. I may not be a coin aficionado, but I'm no beginner to metals.
Next, back in the day it was common for people to try and pull a fast one. I ran across coins that had been altered - usually by means of the mint mark being removed in order to raise the value of a coin. So is it so unreasonable to think that someone might remove the entire date thinking they could get more? I mean, what would they have to lose?? A little time and a single penny. A VERY small investment with a potentially large return -- sort of like buying a lottery ticket. Scams and scamming have been going on since the beginning of time; anything to make a fast buck, or to put food on the table. And don't forget desperation as a motivator. Greed is out there (in force!), but many people have done some really stupid things in desperation. I, for one, am no exception. However, I have never defaced currency - not even with pen or pencil.
Third, I offered my "opinion". I'm not a professional - don't even play one on TV. I'm going on personal experience, past knowledge, past history, and many years of interaction with people. Therefore, it is of my "opinion" that the date on this penny has been removed.
As for the marks, I'm not speaking of the deep grooves that you are seeing. I'm speaking of a very slight rippling effect that "I" believe was made by something similar to a sharp chisel. The area where I see the rippling (for lack of a better word) is just under the shiny crescent-ish mark - above and to the left of the deeper and more pronounced diagonal gouge.
Could I be wrong? Absolutely yes! This is only "my" opinion.
As for the image posted from eBay, I can't tell anything there. There is a strong glare on the right side. There also appear to be many more small scratches on the right side, but that "might" be due to the harsh angle of the light.