5 Francs 1867 - Grading ?

That's a nice looking piece. I'm not familiar with this series but it appears low AU to me.

I'll guess AU by the looks of it.

Thanks all. I am happy I did not attempt any cleaning when I got it and noticed the dirt still clinging to the letters

I have a reasonably large collection of 19th century french silver and gold coins.
A lot of french coins from this period do have such dirt buildup simply because of the number of revolutions that took place as well as the 2 world wars. A lot of stuff was buried at different times.
From experience, these can be conserved and the dirt removed - NGC is the best in my experience at doing that (via NCS) but do NOT try to do it yourself even with pure acetone - I did in my youth and it didn't turn out great.
As for the coin, this is something that is probably AU but I have seen worse slide to low MS (60 or 61). However I am a little concerned about what look to be wipe marks or light cleaning marks. The photo is not that clear but probably if the grader is on the fence they grade AU
Interestingly the 5 francs gold coins in general are pretty rare in mint state so its not that easy to get a better one than your example. I think these coins are in fact undervalued at the moment considering their actual rarity so definitely a keeper.

This as bullion is no doubt at all a bargain especially if it wasn't wiped -sorry the picture was just not clear enough . Congratulations on such a find! It is indeed amazing what sometimes comes as bullion - I suspect if you are not used to this type which is indeed comparatively low relief you might undergrade it. PCGS or NGC won't do that though:)