Here are additional photos - close-ups of the mounting brackets and straps:
This view shows the three mounting brackets attached to the frame. they don't look evenly spaced at this angle but they are.
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This is a close-up side view of the mounting bracket. An angle bracket was used with one side screwed to the frame using self-tapping screws. The other has a rivet through it should the muffler strap loosen, the rivet will keep it from sliding sideways and slipping off.
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This is front view up close:
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Another side view:
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