Retrodisko, If you are going to just order new filters you may use the parts order form found here:
www.highend.com/support/parts/
Simply fill it out and fax it in. If you would like to speak to one of us in technical support our number is 512.836.2242. My extension is 1311 and Zod's is 1306. Thanks.
It all depends on the make & model of the projector that is inside your DL-1. I think there were somewhere like 5-6 different projectors used at different times during manufacture of DL-1. I do know that any new DL-1s are being made with the LX-55...same as DL.2.
You will have to open up your DL-1 to see what projector is in there.