Could you please clarify what do you mean by being unable to locate the seed? Is it lost?
Please note that the only way how to recover your original wallet is to use the recovery seed that it was backed up with. (the one which was presented to you when you created the original wallet)
The original wallet was deleted while installing firmware. This is generally expected to happen if the firmware update process fails, such as, in your case, if there is a disconnection partway through.
You can get to the “recover/create” dialog at any time by wiping the Trezor. In Suite, go to Settings → Device → Factory reset. Keep in mind that this operation will erase the seed that is currently on the device.
In any case, you can only use the “recover” option if you have your original seed. So if you don’t have it, this will not help you.