A number of crosses appear repeatedly in parentages of Colin and Heather Horner's cultivars. These could be seedlings used for breeding:

Flamenco x Rosa Bella (could it be Rosabella by Maarse, instead of the species? Both are 1955 roses)
Elina X Remember Me (= HORaardvark?)
Champagne Cocktail X Alpine Sunset (= HORblush) ---> see HORkorblush
Old Master X Southampton (= HORflash)
Prominent X Southampton (= HORflan, HORsun, HORbond?) --> see HORbondarc, HORbondsmile, HORpekbond
(Honey Favorite X Dr. A.J. Verhage) X Pot o'Gold (= HORnewgram)
Southampton x (New Penny X White Pet) X Stars 'n' Stripes --> see HORalcamstrip, HORlexstrip, HORodd

The seedling Anna Ford X Little Darling was named by Horner as HORbrize.

Thank you, references added!