Oven is really not complicated. It´s just few parts, main body, some insulation and cover which is hold by few screws on the bottom of the oven. 4 pcs are in rubber feets and 2-3 are screwed to main body through cover. When you take down cover, you will see this:
There are 3 control parts: temperature control on top (70 - 230°C), heater selection (off, bottom, top, both), timer (on, off, 0 - 60 minutes). Main power goes to timer and if this is setup to ON or some time, power will go to temp control and after that goes to heater selection. If is everything setup, current flows to positive lead of heaters (negative are connected to ground directly).
Front panel of the oven was held by 6 screws, so when I unsrew them, I got part which can be easily replaceable. I measured all distances between holes for screwes, measured height & width & deep of the front panel and fire up Autodesk Fusion 360. As I also exported my PCB board to Fusion 360 and downloaded SSR from Grabcad, I could imported both of them to the assembly and use them as reference for holes and mounting points. Here is visualization of new fron panel:
I printed on piece from PLA on Prusa MK2 (I have to swap color to white, as I did not have enough silver), which I have at my work and tested it how it fits and I was surprised how good was the result.
I was not satisfied with buttons and hole for USB cable so I made them bigger and printed front panel again. Also I changed height of the stand offs for SSR, as I was not sure if I will need to add heat sink to it, so I prepared some space for it. I also printed some buttons from same material.
Now I have all parts which I need and I can do assembly with new front panel.