Thanks a lot Norjak, I was able to solve the end.
So we were stock at 85042c1305001002320500323d55r. If you remove the first 8 (that I have found on all wowprovider talent link) we have 5042c1305001002320500323d55r left. This start to look like a wow talent. Next step, change all the letters for a number of zero egual to their numeric value -1 (c=3-1. d=4-1, e=5-1). Why sometime you see the latter c and some time you see two zero, that I don't know.
So now we have 504200130500100232050032300055r (didn't remove the last r since it's the last chain of 0).
Time to mix this string with valkyrie-wow calculator (the only one I know that still use a string that you can actualy read the spec out of it).
There the default Valkyie link.
https://valkyrie-wow.org/armory/tool/ta ... 0000000000Swap the "class=" number to the one between the two "_", 5 in this exemple for a priest and replace all the 0 for your string, 504200130500100232050032300055r in the exemple.
Tadam, a readable spec. I know finding a spec on an other website might be easier but sometime it's wowprovider or nothing.