I haven’t noticed any comment on the variable, un/hyphenated spelling of the Group’s name. On the UK London singles (here and on the conventional black issue) it’s ‘Dell-Vikings’. On the Old Gold and Lightning re-issues it’s ‘Del Vikings’ and on the USA MCA re-issue, too.
Here a brief biog of the Group is headed ‘Dell-Vikings’, whilst the narrative explains the difference between Dot and Mercury’s naming.
I have an excellent copy of the orange demonstration sample copy as photo 1 above, but the reverse of my copy has a black blank side B label. It does not seem to have peeled off. Can anyone enlighten me?