If it ain't broke, don't fix it. If it's old, old, old don't compromise it's value by messing with it.
Those are 'Rules of Thumb' in the 'Vintage World' and in general. I respect that...to a point...and then I get out my own 'Thumb Ruler'. As is the case of this 'Tintype'...yes, it really is...so exciting...of my Great Grandmother Martha Jane Marley Carroll. It was in her 100 year old Album...HERE...and like most of the photos, was unidentified in any way.
Also known as melainotype and ferrotype. A photograph made by creating a direct positive on a sheet of iron metal that is blackened by painting, lacquering or enameling and is used as a support for acollodion photographic emulsion. First described by a Frenchman in 1853 and then patented in 1856 by US photographer Hamilton Smith and William Kloen of the UK. The process became very popular during the Civil War and continued into the 19th Century as inexpensive portraits often taken by street photographers at carnivals and fairs as they were simple and fast to prepare.
I estimate this Tintype was taken between 1887-1889I digitally restored it and compared it to photos of Martha Jane as an older woman. Although not a positive ID, it is a good likeness, and the Timeline fits. Of course I did not MESS with the original as you can see in the pictures above.
That is a RULE...and I never, ever break rules...fingers crossed.