I'm actually looking for a 40mm 1815 in white gold (like Jocke's). Great watch, beautifully large. German watches can be forgiven to be big! I've strapped on the Richard Lange PLM in platinum on several times and I did find it a tiny bit thick, but I haven't tried on the white gold one. I don't know if the white gold version is any thinner, perhaps due to its thinner dial?
Regardless, those are some mighty fine beauties you have there! I'm actually okay with the case size. Although I wouldn't mind if either watch was thinner by 1-2mm.