Identifying a finish

[old fence]

Hi there, Can anyone provide me with a link to some decent info on identifying finishes on timber furniture (or provide advice or direct me to an appropriate thread)? . I have an old table which I'm about to fix (current finish has bubbled, pitted and crazed a bit and I'm trying to work out what it is so I can recoat or fix without stripping completely). Google found this (https://www.woodmagazine.com/materials-guide/finishes/what-finish-is-that-anyway)but it didn't help much. Just wondering if there's better information out there.
Cheers,

[double.d]

If it is pitted and crazed i believe there is no other option than to scrape that area but if you do not know the coating then you are likely going to apply a finish that may not take to the current one.
If the top is solid timber then the best option would be to sand it back to bare and apply a quality oil finish.