Prior to the actual printing of the labels, Czeslaw Slania printed many proofs using many types of paper - with and without gum, and various colours and perforations, typically 11-3/4. The legitimate prints that were engraved and printed by Slania with their beautifully defined fines lines are without gum and are easily identified when compared with imitations printed by the offset method.
Purchasing these items can create problems for collectors. So many varieties exist that it is difficult to identify the originals from imitations. The portraits were printed on eight sheets with six of the sheets having multiple designs, ranging from 2 to 4 rows of portraits and 20 to 30 examples of the same design per sheet.
When separating the sheets, different combinations of pairs can be made when rows of two different designs are next to each other (se-tenant). Sheet 7 (Sonny Liston # 22) and sheet 8 (Cassius Clay # 23) are the only two champions printed on sheets of 50 with only one design per sheet.
Only two full sheets of # 23 (Cassius Clay) were printed. They have long ago been broken up and scattered among the collecting community. No full sheets exist, except for one featuring Cassius Clay, which belongs to a Swedish collector, given to him as a personal present from the engraver. I know the collector's identity, but cannot disclose this for discretion reasons.
The sheets of # 22 and # 23 were printed at a much later date than those of portraits # 1 thru # 21. Portraits of "Sonny Liston" and "Cassius Clay" are not possible in "se-tenant pairs of two different designs.