HI Guys. Please Could I Get Some Help From You? (Roman)

It is best to keep the coins, and learn about the types and the Emperors depicted, if not more about the history of the Empire, as a tribute to the hard work by your Grandfather.
They are of more value in that sense than as individual pieces of rarity.
The coin you said you like the most, has a nice green Patina.
It is an AE (copper alloy) Antoninianus (Double Denarius) of the Emperor Gallienus.
http://en.wikipedia.org/wiki/Gallienus
A type similar to the one in the link below, found in Hampshire:
http://finds.org.uk/database/images...ge/id/420060
The reverse depicts the personificiation of Peace (Pax).
http://en.wikipedia.org/wiki/Pax_(mythology)
With the legend "PAX AVG": http://www.forumancientcoins.com/nu...ey=PAX%20AVG

By the time of the sole reign of Gallienus, the Antoninianus coin was becoming little more than just a Copper alloy flan (the disc of metal) with a smattering of "silver" which was more a mixture of Silver-Mercury which soon wore off.

Rich - 15mm is pretty big for some coins!

It shows an emperor (whichever one it is, the flan is too small, id guess Valens) on one side and on the other, a roman soldier spearing a fallen barbarian horseman. The legend, FEL TEMP REPARATIO, means 'Good times have been restored' (you need to know some latin to really understand the sentiment though) - this refers to rome beating down barbarian uprisings. This is like propaganda on a coin really. This one looks to be minted by barbarians - this is common with UK found coins - my last batch had as much barbaric issue as official.

Looks like very weak patina though, so be careful with it. I would give this a soak in distilled water for a week or so to try and curb the decay (has to be distilled!)

Rich,
The small coin is a very interesting coin indeed.

Some coin collectors will instantly dismiss it for being an "ancient imitation" of a Copper alloy coin from the reign of Constantius II, of the "FEL TEMP REPARATIO" series.
http://en.wikipedia.org/wiki/Constantius_II
http://www.forumancientcoins.com/nu...%20REPARATIO

However, from what I have read in "The Coinage Of Roman Britain" by Dr. Richard Reece (http://www.amazon.com/Coinage-Roman...#043;britain), this was indeed a type unofficially created in Roman Britain, obviously from 348 A.D. onwards when the official ones were issued, by the local Romano-British (http://en.wikipedia.org/wiki/Romano_British), rather than "Barbarians" such as Saxons or Franks (http://en.wikipedia.org/wiki/Franks) who dealt in bullion and other Loot.
But they may have been created well into the late 5th century A.D. when Rome officially gave up on Britain.
http://en.wikipedia.org/wiki/Roman_...f_Roman_rule
A very interesting piece of British history.

No need to clean this.

As for cleaning, white vinegar is okay for dealing with the "green deposits" on Silver coins, but for Copper alloy it may well strip off the Patina, so not recommended.

I first got collecting ancient coins in 2007, a chance web search on my favourite Byzantine emperor, John Tzimiskes (http://en.wikipedia.org/wiki/John_Tzimiskes), took me to a link of a Silver "Miliaresion" coin on a website called Forum Ancient Coins (http://www.forumancientcoins.com/ca...ek-coins.asp)that had it for sale.
So I bought it and since then, with a hiatus from 2008 to 2011, have collected ancient coins ever since.

Oh
By no means am I linked to Dr. Richard Reece, but since buying this book in the "Museum Of London" shop back in December, I have found it a good introduction into the Roman coinage of Britain, the types we will most often come across from random metal detecting finds and the kind we see in Newspapers when a Hoard is found.
He knows what he is writing about, which is important!

There are 47 black and white large size photos of coins and 71 in colour.

It is in six parts:
1 Coinage in the Roman World (in 21 easy stages)
2 Coinage in Roman Britain
3 Hoards
4 Site-finds
5 The use of Roman coins
6 Britain and abroad

I was lucky to also get a copy earlier this month, of an "old version" ... same title, different author (Gilbert Askew) published in 1951.
http://www.amazon.com/Coinage-Roman...#043;britain
It has table lists of the coinage, with an Appendix on the "Barbarous Radiates" type of local coinage.
Instead of photos of coins, they are all drawings.

Rather than "jumping into the deep end of Roman coin attribution books" you can "dip your toe" with a cheap, useful book on Roman AE (Copper alloy) coins such as "Roman Base Metal Coins: A Price Guide": http://www.amazon.com/Roman-Base-Me...e+Guide

There is also a very good site by Dane Kurth with A LOT of free information on AE Roman coins, with Excel lists FREE to download, on some common types of AE Roman coin:
http://www.catbikes.ch/coinstuff/coins-ric.htm
Her main site is Wildwinds:
http://wildwinds.com/
Again, A LOT of information on Greek, Roman, Byzantine, Celtic and English coins.