Firmware from 2017 and Not 2015? i3 Pro B

[velvetbrain]

Hey Guys,

Please send the link to the latest firmware for i3 Pro B single extruder 200x200 acrylic non autolevel

I can easily find the old firmware and posts, where are the newer firmwares?

I'd like to replace my zaxis threaded rods as they arrived bent in multiple locations and it's finally annoyed me enough to change to new lead screws.

I assume I'll need to make changes to the firmware for the new steps or would it be possible to just change Z steps from 2560 to 1600?
I assume I have the Sanguinololu motherboard (pictured)

When I issue M115 I get:
=========
FIRMWARE_NAME:V1.0.03 Sprinter/grbl mashup for gen6 FIRMWARE_URL:https://github.com/Ultimaker/Marlin PROTOCOL_VERSION:1.0 MACHINE_TYPE:I3proB EXTRUDER_COUNT:1 UUID:00000000-0000-0000-0000-000000000000
==========
Thanks for your help!

-Lee