Not sure what version you seen as I just made a small change to the CAD file a few minutes ago. One part of it just did not look right to me and I finally figured out why this morning.
Anyway uploaded the change to thingiverse and now I think it looks exactly like the FSP one.
I spent a good part of my evening on this part. Between getting all the measurement from the original part with my calipers. Figuring some angles and radius. Writing down the dimensions on my hand drawn sketches and then finally getting to work in my CAD program. I would guess about 4-5 hours, but I'm still very new to all this.
From what I have seen in the CAD forums I visit a pro could have probably done it in a half hour or less. I learned a lot from it though and it would probably take me less then half the time if I was to do this same part again.