http://www.ebay.com/itm/Custom-Turntable-Dustcovers-to-your-specifications-/112304885052?hash=item1a25e48d3c:g:vQwAAOSwkZhWSz3uEnter your text ...
I had them make me a custom cover for my SP10 mk2 plinth . in 1/4"
They made a beautiful hinged cover for my VPI.
Not inexpensive, but well made and well worth it.
Also, pick up some specialized plastic cleaner.
I use NOVUS PC-10 Plastic Clean & Shine which you can find on Amazon.
It will keep the cover slick and sparkling and will act as a shield to minimize scratching for airborne dust particles.
Check out Gingko Audio. They have beautiful acrylic dust covers specifically for your table, one that sits on the plinth and one that goes over the whole table that sits on the platform. They will also custom make one for you Micro Seiki.
I have one for my VPI that goes over the plinth and sits on the stand. Very nicely made.