Unable to flash MDBT42Q with either Native WebIDE or Chrome - board now locked and unusable [SOLVED #13 post]

The following was attempted using a TTL converter with Tx->Rx and Rx->Tx per:

http://www.espruino.com/MDBT42Q#serial-console

and connect using a Com port rather than Bluetooth.

Used the old standby laptop with the BLE dongle with pairing still in tact.

Tried the web launch from page link from:

http://www.espruino.com/Download#puckjs

http://www.espruino.com/webide

Initialising Tour
Initialising SettingsProfile
Initialising HelpLinks
Initialising Offline
Initialising CoreModules
No code in storage.
GET chrome.storage.local.OFFLINE_DATA = 0 bytes
Handling URL "http://www.espruino.com/webide"
>>> Connecting...
Set Slow Write = true
Unable to open device (connectionInfo=undefined)
ERROR: Unable to open device (connectionInfo=undefined)
ERROR: [notify_error] Connection Failed.
>>> Connection Failed.

Back to the native WebIDE app using the TTL converter and Com port

Initialising Tour
Initialising SettingsProfile
Initialising HelpLinks
Initialising Offline
Loaded code from storage.
GET chrome.storage.local.OFFLINE_DATA = 0 bytes
Web Bluetooth available, but Windows Web Bluetooth is broken in <68 - not using it
>>> Connecting...
Set Slow Write = true
Unable to open device (connectionInfo=undefined)
ERROR: Unable to open device (connectionInfo=undefined)
ERROR: [notify_error] Connection Failed.
>>> Connection Failed.

So it appears the inability to complete the flash process (using DFU) prevents the existing corrupted (previous) flashed version from being accessible. Again tried a hard reset also. Device still unusable.