I found a set of 46mm +0.25 and +0.5 dpts close up lens on ebay if anyone needs that: ebay.de
I ordered the same in Series 8 size (https://www.apotelyt.com/photo-accessory/series-filters) I think their outer diameter is about 63mm but they are not threaded, it'll probably be to small for my lens so I might sell them in the next few days, PM me if you're interested.
I sourced an optician that can provide me a +0.25 diopter 65mm glass element but I have no idea how I could attach that to my lens, any one has experience with custom glass element holder / clamp ?