@paulmbcufc @lakotaubp @wdehoog
SUCCESS !! This is solution for anyone else, using Windows 10
Get ABD drivers
Unlock Bootloader
Allow USB debugging
Use Sony 'Emma' tool to get Latest software & Firmware available on there - (bottom 2 on list) You need to put phone in flash mode to be seen. (Hold volime down whilst connecting USB to PC)
Put phone in Fastboot (hold doan volume up whilst connecting USB to PC)
Go to device manager - check that Android device is showing with ABD device - if not look at other devices for an S1 fastboot device with a warning symbol showing no driver. Update driver - select from computer and put driver location. If this doesn't make the device from other device to Android device, then get ABD from google and use that one.
Get TWRP, twrp-3.4.0-0-dora.img open command prompt in that folder. Type: fastboot flash boot twrp-3.4.0-0-dora.img
Boot up phone, will be in TWRP. Select Wipe, then format data - type yes. Back to advanced wipe - select DATA, CACHE & SYSTEM and wipe them.
Then use UBPorts installer. Put phone into Fastboot, and leave connected to computer until end of process. Manually tell it F8131 as device. Leave fastboot checked, I used channel marked 'stable', I think. Continue on. Phone will boot into UBPorts recovery, and will then install Ubuntu. It will reboot, you'll see Ubuntu robot and 'installing update' phone will then reboot but will be stuck on SONY boot splash screen. So hold down power and volume up, releasing power when screen goes black, until blue LED is on - which means its back in fastboot mode.
Then Flash the OEM binaries from: https://developer.sony.com/file/download/software-binaries-for-aosp-nougat-android-7-1-kernel-4-4-tone/ using fastboot flash oem SW_binaries_for_Xperia_AOSP_N_MR1_5.7_r1_v08_tone.img
Do this by opening a command prompt, again, within the folder. When its done reboot phone. This time SONY screen will make way for UBUNTU TOUCH.......YAY!!!!!