Yeah, it's hard to miss those three legs. The actual name of this three-legged device (so the Internet tells me) is the triune or triskellion. QUOCUNQUE JECERIS STABIT means 'whichever way you throw me, I will stand', which is the motto of the small Isle of Man located between Scotland, Ireland, and England. For historical information about these coins, including an explanation of the inscription 'SANS CHANGER', see the note from Louis Stanley in the comment section below.
Look at this well-preserved coin. The picture was sent to us from MadScotsMen himself. It is in beautiful shape. He also has several other examples, but this is his best one.
Don't clean your coins, MadScotsMen! Cleaning ruins value.
Normally these old coins catalog for about $20 US dollars in worn condition, rising to several hundred dollars in well preserved condition. These values apply to both half pennies and pennies.
MadScotsMen's coin is in such good shape, it should easily fetch $500 to $1000. The catalog also says that these coins were minted in several different metals, and those in brass, silver, and bath metal (a form of bronze) command higher value than the normal copper pieces. Remember that catalog values are inflated values. Use the Terminology page for more information about what 'catalog' means.
Consider having your coin authenticated, graded, and encapsulated by a numismatic service such as PCGS. Once your coin is mounted in a reputable numismatic slab, it will be worth several hundred dollars.
By way of encouragement, Gord Nicols of CounterfeitCoins.com writes to CoinQuest:
Thanks for your kind words about my web site. I have not heard of a forgery of the 1733 coins.
I have heard that these 1733 coins were counterfeited in their day but such a counterfeit in that condition would be as rare as a genuine example.