My, new to me, Durst 601 CLS-66 did not come with glass or proper inserts in the Sivoneg carrier. I'm checking if glass can be "cut to fit" at the local glass shop. I'm unfamiliar with the Durst Sivoneg. I don't see film guides. So to use the Sivoneg with two glasses you just carefully center the negative strip so the masking blades can evenly cover the film edges? Is that how it works? If I can't get glass installed locally will a carrier on the 605 work in my 601. BTW, the 601 is light tight, impressive. I'm looking for the correct Sivopar inserts for 35, 6x645 or 6x6. Are they installed on the bottom of the bookform Sivoneg with the glass left on top? What is the collective experience, likes and dislikes, related to using the Sivoneg?