Denon DK300 Dust cover Broken

You don't need a dust cover, except maybe to keep dust away from the platter when you're not using the turntable.  For that, a piece of cloth will suffice.  If you're really determined to have a lucite cover, you can have one custom-made or keep looking for a second DK300 plinth with intact dust cover.  I just about gave away my DK300 plinth and dust cover, after I bought my DP80 ensemble, I think.  Later today I will check my basement trove of spare junk to see if the dust cover may perhaps be there on a shelf.  I will let you know.  I never ever use a dust cover, especially not when playing an LP.

OMG, I’m registered in so many forums that I just can’t remember what I posted where... :(
For me a dust cover is a must. I live in a dusty house (a house may seem to be dust free, but wait a few days and you’ll see...).Still looking.

My point is that you can protect your turntable from dust, when it's not in use, by any of several methods, including just cover it with a disposable cloth.  But while you are playing an LP, at least I and many others have found that the typical lucite cover adds an obvious coloration.  So I choose not to use a dust cover when playing an LP.  If you disagree, then you'll have to replace the broken cover, or possibly repair it? Lucite takes to glue quite well. If repair is out of the question, my next alternative would be to check the dimensions and see whether you can just buy a dust cover that was made for some other table with similar dimensions. Check eBay for that.