Lionel window insert/diffuser for aluminum coaches?

[Southwest Chief]

I have the Lionel "Super Chief" aluminum passenger car set from 1991 (Lionel 19109....).  They look great behind my old 2343 AA F units.

I have the 2 add on cars as well.  This includes the 19128 full dome.  I really like the way Lionel diffuses the full dome windows with a plastic insert below the glass so you can't see down into the empty car shell.

The 19113 dome observation however does not have a diffuser below the glass so you can see right through into the empty car and see the light bulb and wiring.

It looks like this:

Has Lionel ever made a diffuser to put under the dome glass in this style of dome?

Lionel part part number? 

Otherwise I will likely have to make something out of scratch. 

The ideal car would be a regular round end observation without the dome for Santa Fe since they never had these.  But I've never seen a Lionel Santa Fe round end observation car without the dome with a polished smooth roof that matches the 1991 aluminum car set.

[lionelsoni]

Speaking of making it from scratch, I wonder whether you couldn't just sand whichever side of the insert doesn't have the printing on it.