Who Reissued Decca LPs

I just bought a collection that includes test pressings of Decca recordings in white jackets with black/white printed sheet that reproduces cover art and mention 1996 release. Also describes 180g German pressing (Pallas?), max =1000pcs. Are these Speakers Corner test pressings? Having trouble finding info on another company reissued the Decca/London catalog as described? The label on the LP is totally blank. As an example, one is reissue of SXL 2221 Ansermet / Rimsky-Korsakov.
Thanks for your assistance & cheers,

Spencer