I'm guessing this one (the bush version of the name) was bred from Bonica. If I had to guess a pollen parent, I would consider Tamango. Less sure of my guess of the pollen parent, though.
So it was Centenaire de Lourdes via Anne de Bretagne giving that dominant peduncle and foliage type. Maybe someday we'll find more out about Centenaire de Lourdes.
Reading down the comments, it seems that the name associated to the climber tag is the name used in Africa. That may explain the size behavior differences (a little, I guess).
Also wondering if there is a bush version and a climbing mutation. The photos seem to be very disparate in plant dimensions. (Or I'm just going crazy, which is possible).
Perhaps not so insane. A picture from Aurelija shows at typical floribunda about a metre high whilst a picture from David Elliott shows a substantial climber against a wall.
There is another explanation: The breeder code 'Meinoiral' for 'Blossom Magic' as reported by Ludwig's Roses is incorrect. MR XI and the Encylopedia of Rose Science state 'Meimanoir'. We will correct this listing.
Do you know of a nursery selling 'Meinoiral' as 'Blossom Magic' or do you have a REFERENCE confirming that 'Blossom Magic' is an accepted synonym for 'Meinoiral' ?