Not really an answer to your question, but just to make you aware of some options:
Have you considered using subkeys for each of your machines, signing things with those, and keeping their master key someplace safe? That would limit your exposure if one of those machines is compromised, since you could revoke only that machine’s key while the others remain useful (and the signatures they have issued remain valid).
Are you setting expiration dates on your keys? That can bring some peace of mind when you lose your key/revocation data.