I hear growers of Riethmuller roses are having trouble telling his 'Esmeralda' apart from Lambert's 'Gartendirektor Otto Linne'. 'Esmeralda' is a floppy, low plant; GDOL is a stiffly erect one. 'Esmeralda' flowers start off magenta, not pink. But also, the leaves are quite different. I've put up a photo of GDOL I received from Trewallyn Nursery in Bundaberg, Queensland. No Riethmuller Lambertiana has leaves anything like as glossy; GDOL's are are close to those of a 1950s Kordesii hybrid.
The photo in the middle is of a well-authenticated 'Esmeralda' in the Victoria State Rose Garden. To the right, an authentic 'Spring Song' showing furrowed leaves and little gloss unlike either of the others.