There is another 1858 smaller numerals (over)date obverse die which is paired with the exact same reverse as the 1858/6. Furthermore, it’s obverse looks very similar to the 1858/6 obverse!!
Please carefully examine the set of 4 pictures below, which shows flaws, and overdates, for both these obverses. Note in particular that the flaw commences in between border teeth for the 8/6, but the flaw commences in the centre of a tooth for the other type of overdate. Also, the flaws exit the base of the C’s at different locations, which means 2 different dies.
I would welcome views as to the other overdate e.g., is it an 8 over 8, or even a different type of 8/6 which this time has no bar down the left-hand side.
I have just seen that there was one of these on ebay, and bought it:-
1858 Penny (WW) - Victoria British Copper Coin - Very Nice | eBay