I have recently started using B757-300 in the game and I notice how they don't have Winglets as an add-on. If I looked at the picture you can clearly see that B757-300 have winglets fitted just like B757-200. Could this be edited in the future?
I also got several articles from Boeing about blended winglets on this aircraft. Here is the detail: http://www.boeing.co...9_article03.pdf
Also here is some picture of several airlines that fitted their B757-300 fitted with blended Winglets:
Hope this help. Thank You