If the DW soak and the soft nylon toothbrush (some recommend cutting the bristles to make them shorter) are ineffective, then (not requiring specialized equipment) you need a small, very sharp scalpel or an X-Acto knife (crafts knife) with a new small blade and (which I'm sure you have) a magnifier, say 10X, supported to leave both hands free. And good light and patience. With the coin dry very carefully set to work.
Since you have a lot including some quite common coins, start with one of them, a relatively large one, and see whether you can cultivate the touch needed. As 'golden ancients' says, https://www.forumancientcoins.com/board/index.php?topic=55861.0 , Reply #3, don't hurry and don't use more than the gentlest pressure. As for the WD-40, the chemically competent among us have explained why it will not hurt the coin, though its effectiveness varies according to what you're dealing with. It's the stuff that will help open a corroded lock, available at any hardware store and at many supermarkets.
Anyhow, though they're not Republican, take a look at the work at the place that I linked to.
Somewhere, I remember, Curtis Clay describing how he worked with a scalpel, but I don't find it.
Pat L.
Thanks
Pat, those are some unbelievable restorations. One coin that looks like it's under the crud is a
Crawford 63 "C"
mintmark As; there are only three known specimens all extremely worn, this crud-covered coin looks like it might hide a better coin than the others, and there are a lot of collectors of
Republican Asses for which this is a key missing coin (including myself!). On the
face of it my
good experience in RR bronzes tells me an important
rarity is hiding in there so I want to take it carefully..
It's the bright green coin in the bottom left hand quadrant of my pic by the way; the pic shows the
reverse rotated clockwise 45 degrees. The coin doesn't look a lot better in the hand, but the underlying relief is quite high and appropriate lighting shows a prow
style,
Janus style and letter C position size and
style that matches the known specimens. The bright green coin in the bottom right quadrant that looks just like a green splodge with brown tones, is hiding a MA
Semis, also a very
rare coin; my below illustrated example
http://www.flickr.com/photos/ahala_rome/3537908345/ would be considered a very decent specimen so that shows how elusive these are. For the
style of coins with "C"
mintmark see the other pic
http://www.flickr.com/photos/ahala_rome/3752894280/ in this case I believe my coin is probably the best known specimen; I'd just like to find the As to match under the green crud....
The quite decent looking
semis in the middle right of my original pic looks to me like a
Crawford 112/4 staff
semis; that by itself rates as
rare (although not as exceptionally
rare as the Sardinian coins) and it was that single coin that prompted me to buy the entire lot; whilst the styles matches, the coin is too light and the letter S appears above the staff rather than before the prow, so I'm not sure if it's a regular issue. The coin at the far right of the picture is a
Crawford 41/9 post-semilibral
sextans http://www.flickr.com/photos/ahala_rome/3537902497/ one can see the
head of Mercury facing right in the pic; that just below it, in the extreme lower right hand corner, is probably an As of L.TITVRI L.F SABINVS dating from 90BC
http://www.flickr.com/photos/ahala_rome/3585417686 with a
Victory figure in front of the prow.
All in all, this being my first test of
buying RR bronzes in a bag rather than individually, I think it's been a happy outcome even though pending restoration I can't be sure any will be better then existing coins and thus enter my
collection.
cheers