File's description:

combined_img.jpg - is photo of the connected boards
opened_img.jpg - is photo of the opened board
gps_sfn_conn_v2.pdf - Schematic of the add-on board
gps_sfn_conn_v2_pcb.png - PCB drawing
w5500-lx9-ad9957_sfn_addon_v2.tar.gz - Eagle Schematic and PCB project. Size 7x5 cm.
stm32f0_gpsdo3_rel.tar.gz - This is a firmware repository for OPTIONAL GPSDO, based on STM32F0 MCU. Don't use it if You are using LEA-M8F receiver.