The 161 bytes offset might be explained by corruption in an encoded version of the key. 161 bytes in binary data would be ~ 216 chars in base64. With an (unusual) line length of 72 the corruption would start exactly at the 4th line.
But: Mail clients should use 78 chars per text line, and GPG encodes base64 in lines of 64 chars length, so ignore my theory ;-).
Comments
The 161 bytes offset might be explained by corruption in an encoded version of the key. 161 bytes in binary data would be ~ 216 chars in base64. With an (unusual) line length of 72 the corruption would start exactly at the 4th line.
But: Mail clients should use 78 chars per text line, and GPG encodes base64 in lines of 64 chars length, so ignore my theory ;-).