About this deal
It looked very similar to your watch. It took me about 45-60 minutes and I was rubbing the crystal using polywatch really hard using the cloth that came with the polywatch. Would never rub it that hard on a hesalite.
not to diss polywatch ... but I bought a bottle of "generic poly carbonate headlight polish" ... big ass bottle for 0.99 ... its the same - works the same I apply Polywatch with a slightly damp cloth and rub in a circular manner. Works great on acrylic crystals and, with enough elbow grease, will even remove some fine scratches from mineral glass. Plastic watch glasses scratch very easily and replacement is not always possible, particularly where the case is plastic. Polywatch slightly disolves and grinds down the surface of the plastic watchglass to smooth the edges of the scratch and fill the gaps with dissolved material. Polywatch is so mild an abrasive I have never bothered to tape off anything and I just make sure to keep the cloth with the polish on it on the crystal alone and not rub the Polywatch on the remainder of the watch.
The brand
Article size of the abrasive material so that you correct the larger scratches first and then get finer and finer to finally achieve a high shine with the final grit size....I would be skeptical about a single paste, unless perhaps the paste is made up particles that break down into smaller and smaller particle sizes as you work it into the crystal.
i just use a generic "polycarbonate headlight polisher" from pep boys or so - I had sitting around in the garage ... works just as fine ... never had a scratch that I couldnt get rid of
The products
As with all polishing, move through grits from coarse to fine, making sure that you remove all of the previous marks before moving on, and finished with Polywatch. Please excuse the dust... What I do is use microsandpaper, starting with 1800 grit and working to 12,000 grit, this allows me to remove virtually all the scracthes, as a final step, I use Polywatch.