Repair of Agilent DSO1014A after failed software update

[Ulitos]

Hello everyone!
I have bought a used Agilent DSO1014A scope on a local test equipment store. It was in perfect condition, like wasn't used at all.
The only defect was a broken 50% trigger button.
Really, i don't know why i opened the software version menu, where i have read "The latest version of DSO1000 Series scope firmware can be downloaded from blah-blah-blah link" and got an obsessive thought to update scope's firmware.
I have opened that link, and, suddenly, really found software update 011.04.00.04.06 SP5  from 2015!
After that, i downloaded that update file to flash-drive and, as described in scope instruction, updated scope's firmware. That was a terrible mistake.
After reboot i saw that text in almost all menues dissapeared, or displayed incorrect, as you can see at picture.
I have tried to change languages, update firmware again and again and nothing happen.
Integrated help system works correct and display text well in all languages. All functions and measuerements still work as usual.
Moreover, time to time scope doesn't start up properly and just light up some buttons, sometimes it freezes in random time.

I have contacted Keysight support with that problem, and have a pretty long correspondence, but only answer to all my questions and suggestions was just "We tried to restore old firmware on fabric and failed - scope's system rejects old firmware update files. Your instrument is 12 years old and is out of date, please buy new one"

On one local forum i found dude with similar problem - he got troubles with SDS scope after firmware update, and just flashed its memory with memory dump from another similar scope. Of course, he failed, as replaced factory calibration data of his scope with data from another scope.

After reading story of his bindings, i found a plan, how to repair my scope:
1. Collect some number of memory dumps from similar dso1014a scopes with old identical firmware.
2. Compare all dumps in hex editor to found, where factory calibration data and serial number is.
3. Merge calibration data from memory dump of my scope with old firmware from another scope's dump.
4. Replace memory chip ( s29gl064n90tfi04 )in my scope to new one and flash it with new monster dump.
5. Pray The Machine God.
6. Turn scope on and see if it still work.
7.
8. PROFIT

So, i ask your suggestions and help with my trouble.
I hope, you will understand my not perfect english.