Definitely recommend getting a replacement IR filter Sensor glass. You can order this from Leaf or MAC group in the US. Ping Yair (yaya) for the part number - he helped me with that information for my Aptus 65 after I broke my sensor glass.
It might cost you $1k, or maybe less, but it'll make the back definitely more sellable. Of course, the other option if you don't want the hassle is to discount it and provide the details for the buyer to get a replacement sensor glass cover.