That's exactly correct. The engraver back in Ragusa in the 1700's did not do a good job on his portrayal of the number 5, it can easily be mistaken for a 3. The reproduction shows the exact same thing.
"The documentation that came with my coin when I bought it in Dubrovnik back in 1973 was in SerboCroatian and I had ChatGPT translate it: ""Silver Thaler of the Republic of Dubrovnic, 1735. It is confirmed that this reproduction, with a diameter of 44mm and a weight of 28 g, is minted in silver (566/1000) in a limited edition of 5000 pieces."