GPG and 1024-bit (or multiple) subkeys

[Charles Franklin Bernard]

> > So I added another subkey, 2048-bit, but the customer says GPG is
> > looking for a 2048 subkey *by itself*.  Does that make sense?
>
> Not especially.  Subkeys don't exist in isolation.  They only exist as
> part of a larger key.
>
> Your customer's request doesn't appear to be particularly well-phrased.
>  That's going to limit any help anyone on the list can provide.

"By itself" meaning a key without any other subkey.  They want us to
generate a new public key with only one subkey, and that at 2048-bit
instead of 1024.  I suppose we could also make a copy of our existing
public key, then delete the 1024-bit subkey (keeping the 2048-bit
subkey we recently added), but I'm hoping there's a command line
argument/flag for GPG to encrypt a file using a public key with two
subkeys, specifying the 2048-bit subkey and ignoring the 1024-bit
subkey.

Thanks,
Frank