CBID - Chess LP-1498 in silver - explained

In December Morten Reff reported here about a strange copy of the Fresh Berry's album having a silver label.
He wrote:

A couple of weeks ago I bought a copy of this well-known album having a label I have never seen. It’s a silver Chess label. I have not seen any other Berry LPs on Chess with this kind of label colour. The copy I got is the mono issue. The question is, was it also available as a stereo issue?

Reader Thierry Chanu was able to explain this unusual label:

This is one of the rarest original US issues ....... only four copies known!!!
It is the first US "DJ COPY" for this record. If you look at the label carefully, especially the side one, (use daylight and/or clean glasses) you will notice the "DJ COPY" writing.
CHESS seems to have used this bad silver paper in 1965 very briefly. Here's the label of a Ramsey Lewis Trio album on ARGO.

And to answer Morten's question: There is no stereo issue for this silver label. The company's DJ COPY/WLP records were only in mono at this time.

Morten agreed. When you look very closely at the label you may see the text DJ COPY stamped below the matrix number. Here is a detail of the silver label as well as the full standard white-label promo (WLP) DJ copy of this album.

When asked how he knows of only four copies of the silver label album, Thierry told me that this is from his own experience monitoring record offers for more than thirty years. He has seen this silver label copy offered only four times so far, one being Morten's.
Thanks, Thierry!