Chris....After looking at them some more...IMO ... it looks like the vent area on the 1:1 car has more of a radius to it. yours looks more like it angles back....I also tend to think that the vent its self is a bit wider on the 1:1 car...the distance between the side of the vent and the rivets on the base piece look to be less than what you have...Might just be me but that kind of what I am seeing whe I look at it...and I think the base might be a tad thick compared to the 1:1.
What you have is way better than I could do though ...so not sure I should be putting in my 2 cents worth anyway....