Re: 1,958 Cu. Ft. 70T Covered Hopper Cars
For MILW 99000-99034 the MIlwaukee Road Historical Association (MRHA) has a fresh in service shot of MILW 99031 with a MS 4-60 paint date. Taken on the west end near Othello, it is pictured in "Wade Stevenson's Milwaukee Road," a book mostly composed of action photos taken in the 1950s and 1960s. There are also a small handful of roster shots in it.
Non-members of MRHA can purchase this book here: https://www.mrha.com/store/product.aspx?Product=213&Name=Wade+Stevenson
I also have a photo from this series in my collection - sending to you off list.