Cannonmn,
The French bronze gun is exhibited in the Museo de la Atarazanas located in the old "Colonial Zone" section of Santo Domingo, Dominican Republic. The museum is not in a converted church, I think the "Oldest Church" in the title of the vid is in reference to the church shown near the end of the video.
It can't be the French ship Le Dragon that the bronze gun was recovered from, because her armament consisted of 18 iron nine-pounders, and some swivel guns.
"Le Dragon was originally an English privateer travelling probably under a Royal Warrant or letter of Marque. She was captured in August 1781 in the English Channel. She was taken into the French Royal Navy and the King of France paid 9438. 16. 6 livres. She was then transferred to Lorient and converted into a Corvette with a brigantine rig. She was “pierced” for 20 cannons and was eventually armed with 18 Scottish nine pounders (the last of the nine pounders just before the “Carronade” was first made) made by the Carron Iron Foundry in Falkirk in Scotland and sold in America. She was rigged for up to 12 swivel cannons and had a crew of up to 120 men."
The 'North Caribbean Research' website states that two bronze cannons have already been raised from "Napoleon's lost payroll ship," and that there should be 58 more yet to be recovered. A 60 gun warship would be classified as a "Fourth Rate, Ship of the Line" with two gun decks, the Le Dragon was classed as a Corvette which is a smaller ship.