When I worked at a local BMW shop I often had to dissassemble and re-arrange the tumblers in new replacement locks to work with the original key, because to order a new lock with a matching key woud take way too long.
Later, I had an old Honda Accord where the PO had installed a new ignition lock, but it was a pain to fumble for two similar-looking keys all the time, so I pulled the ignition cylinder and was able to re-arrange 5 of the 7 tumblers to work with the original key.
The two that didn't work, I just left out.
You'll still need to get your replacement lock apart. Or use it as-is. Either way, maybe you can order a new key for it.

Happy Motoring, Mark

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DrDKW