made a mistake while cashing out a casascius coin

i made a big mistake while trying to cash out a 'casascius' coin last week, just wanted to confirm with anyone who understands the technology well that my understanding is correct and there is no way to get it back:

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1. imported private key containing 1.0 btc into latest version of bitcoin core running a Windows VM.
2. made a small transfer of 0.001 btc into another wallet, everything looked great.
3. [this is where the error was made], did not make backup of the wallet, and due to disk constraints, i deleted the Windows VM to free up space for another VM, thinking that as long as i have the private key to the original token i should be fine.
4. create more space on another Windows VM, installed latest bitcoin core client, re-synced.
5. imported same private key, expecting to see 0.999 btc. instead saw 0.0 btc... because the action in step #3 essentially moved the "change" of 0.999 btc into a potentially new private key that i no longer have access to since i deleted that Windows VM....
6. attempted to undelete the Windows VM unsuccessfully essentially losing access to the remainder 0.999 btc.