One electrical wholesaler in my area has an arrangement with a small shop that fabricates lenses and diffusers to order. You take your old one in and few days later, they call with price and delivery promise. Then you choose to pickup both the old and new at that date or just get back the old one.

Thanks, if you have taken advantage of this service, do you mind telling me about how much you have paid for it?

The one I bought was a simple white plastic cover for a single tube fluorescent bath fixture. The cost was less than the price of a new fixture and I also did not have to install the new fixture.

Look under 'plastics' in the yellow pages.

Most cities have at least one shop that cuts plastic down to size.

They should be able to cut anything you want.

I am sure that someone can cut sheet for me. The trouble is that I would need fabrication and that will probably be prohibitively expensive. What I have is a 5-sided, shallow box. There are slots on the sides of the box that mate to tabs that project from the troffer. To remove the box, you slightly deform the sides to drop one side while holding it to prevent it from falling off the tabs on the other side.

"tabs that project from the troffer."

Still does not sound all that hard to cut.

You might even be able to cut straight and then affix the tabs.

Solvent welding is not all that hard and the 'cement' is not expensive.

True enough, however, the tabs are metal, punched from the sides of the troffer. They go into slots in the plastic diffuser.

Why not replace the fixture? Have you priced replacing it?

That way you'd have a new ballast also.

Thanks. I already have a box of primo ballasts to use up.