well, this ship was originally an royal navy ship, but was captured. the dutch were a large seagoing nation then as well, so........ well you get why I'm not sure

While the Brits started to experiment with copper sheathing of their ships already in the 1760s, with some progress reached in around 1777, and then began to on a wider scale implement coppering on 1st thru 6th rates, by around 1779/80, other navies, most notably the Spanish were quick to follow. Already by 1785 the Spaniards had implemented a full-scale system to copper-sheath their vessels, thus adding even more to their legendary longevity. The French program was seriously disturbed and set back by the onset of the Revolution, which funnelled the valuable metals into other, more imminent uses. But by 1800 nearly all French men-o'-war were thus protected, and, since the Batavian Republic, later a Napoleonic Kingdom was a part of France at this time, it follows that Dutch vessels were so treated as well. At the Camperdown (Kamperduijn), in 1797, Adm. de Winther's fleet was, almost in its entirety coppered; so was, too, Adm. Duncan's. Also, at Trafalgar most French, and all Spanish vessels had copper bottoms, as had the entire British fleet opposing them. So, my answer is: since this is a former 6th Rate, that is the lowermost rate where coppering was done, you should copper the bottom. Unless for electrolyte-conflicting reasons the copper bottom quite literally would have fallen off (it did happen!), there's no reason to believe that the practical and prudent Dutch would've removed it - unless, of course by direct Royal Command from King Louis I of Holland (that is Napoleon in proxy!) - So, again, copper it!