Assistance with decryption failure, gpg unable to find secret key that actually exists

[Spoofy32 .]

Greetings!

I am currently having an issue with decrypting a simple text file encrypted
by gpg using a key pair that I was able to successfully import (including
the private key). The key material in the secret key packet is unencrypted
to keep things simple. Despite both the public and private keys being
present when I list them with gpg --list-keys and gpg --list-secret-keys, I
receive the following error messages:

gpg: public key decryption failed: Wrong secret key used
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