The screen is indeed doable! That was certainly the most frustrating part of the build:
-I placed my cutout 5mm too high ony first enclosure attempt.
-Programming the ATTINY85 is relatively easy...with a bit of research. Parasit offers the .HEX file on their website. There are ATTINY84-based USB programming sticks available that have a dip 8 socket pre-installed, although you can program them with an Arduino and breadboard setup as well. The way I found to write the hexadecimal code to the ATTINY85 involved using a program called AVRdude, which has an MSDOS interface.
I am NOT proficient with MSDOS, but after about a day and a half of experimenting I was able to figure out the process. When you figure it out, it's pretty pain free. I was very frustrated for much of that first day, though.
-support of the OLED on the underside is problematic...especially since I socketed it. I could use some m2's, but they would interfere with the text...layout on this one has caught me off guard a couple of times. I may end up stuffing a bit foam on the bottom to keep it stable...not a huge problem, just something to consider.
@fig thanks for the kind words! I haven't forgotten about making you an enclosure either ;-). I've been a little lax on finishing projects recrntly...working out all the little kinks in my CNC3018. Its JUST about there. I have a plan to relieve the last little bit of Y axis play, after that I'm hoping to get seriously rolling.