Three versions of Wemos D1 with 128×64 OLED:
Same PCB aka ESP12F OLED
OLED 128×64 with SSD1306 controller built on the same PCB with Wemos D1 Mini usually named “ESP12F OLED” at Aliexpress.
STL: https://www.thingiverse.com/thing:2853146
Layered (Combo)
Using Wemos D1 Mini and put OLED 128×64 SSD1306 on-top/bottom of it, keeps it same width and height but a bit thicker.
OLED GND - Wemos D1 Mini GND (pin-to-pin)
OLED VDD - Wemos D1 Mini D4 (pin-to-pin)
OLED SCK - Wemos D1 Mini D3 (pin-to-pin)
OLED SDA - Wemos D1 Mini D2 (pin-to-pin)
STL: https://www.thingiverse.com/thing:2853148
Side-by-Side (ComboSBS)
Using Wemos D1 Mini and put OLED 128×64 SSD1306 side-by-side (SBS) with hot glue, is a bit cheaper than the “same-PCB” version.
OLED GND - Wemos D1 Mini GND (wire)
OLED VDD - Wemos D1 Mini 5V (wire)
OLED SCK - Wemos D1 Mini D2 (wire)
OLED SDA - Wemos D1 Mini D1 (wire)
STL: https://www.thingiverse.com/thing:2853149