Possible Clues:

• Like poorly cleaned glasses
• Like poorly cleaned windows
• Having different bands of inconsistent quality
• A sizzler, artist producing blurred lines?
• Republican tucked into cut of beef, say, ultimately of uneven quality
• Like a poorly cleaned mirror
• Having lines of differing colours
• Oddball forbidding female in pig enclosure produces particular bacon?
• Such bacon uneven in quality?
• Valuable cargo sure to be lost in weather that's unreliable