It looks like you're using the clear plastic sheet that hardware stores like B&Q sell. This isn't actually acrylic (perspex), but clear polystyrene, and is horrible to work with in my experience. I'd recommend getting some better quality acrylic sheet. If you're in the UK, Trent Plastics is a great supplier, or even have a look at ebay, and you'll probably be able to get a load of small sheets (150x150mm or similar) for very little money. You'll find the finish you can achieve will be much better. Looking good regardless.