You can try create masks based on selecting focused areas with latest Phtoshop iterations, but I think it wont work very well with your case because some more uniform untextured areas of your tank will likely be considered as blurred too.
Ive tries t in the past with stone artifacts where depth of fiels was not enough and I das to remove blurred parts.
I think this feature (masking by lack of sharpness) should be available as a separtate process for masking and even built-in in some smart way to rule the key points extraction and depth maps creation.
Regards
GEOBIT