Well right now the images are a hazy mess with no contrast or detail at f0.95. More 'knocked-out' than 'dreamy'. Once I figure stuff out I'll post pictures to illustrate.
Retinax ideally I'd find a broken one for the parts. Buying or borrowing is an option but measuring curvature accurately requires specialised equipment.
I guess this thread shows my wishful thinking. Even if I knew the exact specs of the element I don't know that it could be sourced unless it's coincidentally off-the-shelf like 50mm FL symmetrical bi-convex in BK-7.