~snip~
once I've checked that all this works I might upgrade the current ledger as well. am I being too cautious?
It would be good if you check which firmware version you have on the Nano S, because such an old device probably has a firmware version that cannot be upgraded. Practically, it is a device that may be completely unusable because it cannot work with Ledger Live, and most likely not even with Electrum, not to mention outdated coin apps that would represent a security risk even if you could connect the device with some software.
I am not sure if you need the newest Ledger Live versions before being offered a firmware upgrade. I never tested it.
It is always recommended to have the latest Ledger Live before a firmware upgrade, and even if the OP tries with some older versions, he probably won't be able to upgrade a device with such old firmware. There is only one way to find out the answer to that question.
Firmware versions 1.1 and 1.2 cannot be updated with Ledger Live Desktop. Please check the firmware version.
https://support.ledger.com/hc/en-us/articles/360002731113-Update-Ledger-Nano-S-firmware?Electrum will probably work with those lower firmware versions.
One more good reason to keep the firmware updated.
the old chrome app was deactivated , which was responsible for those updates in old firmware