Re: Advice on ellipsoidal/leko
The D size gobo isn't one of the common sizes, and none of the offerings that are readily available will accept that size with standard parts. That said, the D size gobo is smaller than most of the normal sizes, so could be made to work with some effort. Here are your options:
1) Find a unit intended for D-size gobos (Wikipedia claims that 2 such units are the Martin PR-1 and the Ecospot 40)
2) Get a custom gobo in the appropriate (A or B) size for the common ellipsoidal fixtures
3) Make a custom gobo holder for your ellipsoidal of choice
4) Use something like a Rosco Imagepro to duplicate the gobo
Option 3 is going to be the quickest, but will be challenging if you have glass gobos. For steel, you should be able to make an adapter ring for a standard gobo holder. If you go with that option, the Source 4 Jr. is going to be your best option, as it uses M size gobos which are the closest in size to a D size.
Option 2 will be the easiest to work with, and will give the best image quality. Option 4 is similar, and may get you something quicker.