My Lofrans Tigres suggests a 160 amp breaker on their web page. The suggestion to size your breaker to the wire size is good advice also. Charts for figuring breaker size by wire size is available on the web. However one never knows if someone put in wire larger than needed for your windlass or skimped and put in barely adequate wire. If you've been running the windlass without problems for some length of time, I'd assume it's adequate if I had no windlass manufacturer information to go on.
I will relate my experience coming back from Alaska last year. I noticed a few times during anchor retrieval that my windlass would continue to run for a short time, a second or so, after I let off the foot switch. Just a second or two, but I did notice it. By the time we got back down to Campbell River, after a 12 hour run from Port McNeill, I went to drop the hook and nothing happened when I pushed the switch to let out the chain. I found the breaker was tripped. When I reset the breaker the windlass would jiggle the chain and it would immediately trip again. So I tracked it down to the foot switch getting water into it thru sun baked rubber cover. I replaced the switch and all is fine with the windlass again, we continued to anchor many times afterward.
Why did I tell you the story? Because the breaker is sized to the windlass and when it brought the anchor up tight to the pulpit, it tripped the breaker rather than continue to pull and burn up the windlass or inadequate sized wire.
Now the idea of fuses rather than a breaker is good too, you can fine tune what's really needed. But, how many fuses will you carry and at what cost? I reset my breaker probably 5 or 6 times while figuring out what the problem was.
Using a clamp on ammeter as previously suggested would give you the amperage when retrieving your anchor and all your chain but doesn't take into account an anchor well stuck in the bottom which we all pull against every so often.
So what's the magic answer? I don't know. But the size smaller windlass than mine, the Cayman, suggests a 110 amp or 150 amp breaker depending on which wattage motor you buy. Take a wild guess as to what yours needs by looking at similar sized units and give it a try.