Constantine II real or fake? (newbie sorry)

[MTcoin]

Hello, I’m new here, my first post. 
I know very little about these coins.   I found while at work a couple weeks ago.   I’ve spent some time (several days) reading and researching to better understand what I have here.   I wonder if its fake or not, and if what I’ve researched about it (if real) is accurate.  I will do my best to use correct terminology here, so this is what I’ve come up with.  Sorry if the photos are not clear, have done the best I can with what I have to use.   I tried to insert them to this post, but was not able to for some reason, so they are attached.
 
Weight: ~ 5 grams
Circ:  18.3 to 19.3 mm   

My determination is the Obverse bust is Constantine II   "Constantine the Younger, Noble Prince, Caesar."  I have looked at the coin under a magnifying hood with some better lighting and can identify all the letters on the Obverse side. 

Obverse Legend:
CONSTANTI    NVSIVNC   


The Reverse is a bit difficult and I’m making this determination from what it “appears” to be from online sources of what should be there in relation to the type of captives. 
Reverse Legend:   VIRTVS   EXERCIT 

It has VOT  XX with three dots on the top of the banner.  The right captive’s arms show a gap between the body and its arms.

The three letters below the captives look to be:
1st:  P – (for Primary?.. this letter is very clear to me)
2nd:  looks either to be a  I or a T
3rd:  looks either to be a A or R 

So I’m thinking stuck at Treveri  between 316 and 337 AD.   

Its odd to me that the obverse is much clearer than the reverse, so perhaps re-struck or fake or..?

[MTcoin]

to add to my initial post, that during my online searching I found this coin for sale.  The obverse and bust looks very similar to my coin, but its LICINIUS II.
 https://www.vcoins.com/en/stores/lucernae/90/product/rare_licinius_ii_caesar_317324_radiate_follis_treveri_virtvs_exercit__str_standard_inscribed_vot_xx_captives/1346639/Default.aspx

[Victor]

Hello and welcome

Your coin looks genuine...it is not unusual for the obverse and reverse of a coin to be in different condition.

You are correct, your coin is Constantine II. Your obverse is CONSTANTINVS IVN NC and the reverse is indeed VIRTVS EXERCIT

Your mintmark is dot PTR; which does mean Treveri (modern day Trier) and was struck A.D. 320.

The three dots at top of banner are part of the banner. The position of the captives often varies as these coins were struck from hand made dies, so even the same engraver's dies will be a bit different.

here's a good link that has .pdf's of some common types-
http://www.catbikes.ch/coinstuff/coins-ric.htm

below is a coin that I just got that shows a great difference in condition between obverse and reverse.

[MTcoin]

Thanks for the post Victor.  I've looked through the link you provided and through some of the spreadsheets available there.  I can't seem to find anything similar to my coin listed in there, but I'll keep looking through it.   

Its been a very interesting journey for this coin, and so I'd like to share how I found it.  I work for a municipality in the public works dept.  Some of my tasks include collecting the coins from street parking meters.  Usually we have anywhere from 150 -250 lbs in coins when we do a collection of all the meters.  Now, its very common of course to find foreign coins in with US coins, so what we do is push and pull a ~10 lb. brick magnet through the coin pile (usually divided up into several piles at this stage to make it easier).  The magnet pulls out about 90% of the foreign coins and tokens.  This gets us ready to run the entire pile into the machine sorter and bagger.  The machine also diverts any foreign coins, or damaged coins or other objects into a divert bin. 

So the entire pile of coins (after the hand magnet) was placed into the top of the machine and I was running it on that day.  I happened to look at the top of the pile and there was this coin, face up, looking right at me.  I noticed it right away and picked it off the pile.  It would have been diverted by the machine if I were to not have noticed it anyway, but still it was just right there... right on top of this huge pile of 200lbs of coins.  Now its in my hands, and since the municipality only cares about US coins for revenue purposes, this coin is now mine.   We get a lot of worldwide tourism, so it probably came from someone overseas... or not...who knows.  The other thing to mention is that although we get pennies, they actually do not count for any time on a parking meter, and this coin looks close enough to a penny, that someone probably didn't realize what it is.