Restored Garden Bench

This is a project that I did in partnership with my brother-in-law (Bob) this Summer.  A little history first.  The original bench that you see in the first two photos was a gift by our two families to our wive's parents several years ago, where it stayed in their back yard.  (I believe the original slats were oak.)   When my in-laws moved, the bench went to my brother-in-laws' home, where it stayed, and eventually got into this weathered state, and the paint on the metal was more worn than these photos depict.   When I saw the bench this past Spring, I suggested to Bob that we refurbish it using better quality wood.  He liked the idea, and he removed the old wood, stripped the metal and repainted it.  On my suggestion, he also ordered a set of 50+ custom-made carriage bolts that had nicely finished heads.   We used 2 12' 5/4 x 6" Ipe decking boards for the replacement wood.  I cut the planks to length, planed them to ~1", ripped them to 2 different sizes identical to the original boards, and then used a 1/4" rounder bit to take the edges off.  When we go together to assemble it, we drilled  holes on both ends of the slats to accept the carriage bolts.  We ran into a snag, though, as the carriage bolts he ordered were 1.5", and the Ipe was too thick to allow washer, lock washer and nuts.  So, I ended up replaning the slats to 3/4" thickness, which was a shame to waste all that wood, but the custom bolts were fairly expensive, and so reordering them in a longer length wasn't a viable option.  In the end, the 3/4" thick Ipe was much stronger than the legacy oak.  Lastly, we finished the Ipe using Tung Oil.  Last photo shows the bench sitting on Bob's front door stoop.