Yes, there are photos of cars in this scheme in Morning Sun Books' D&H Color Guide to Freight and Passenger Equipment.
On page 70 is a photo from the collection of the late Jim Odell (one of the book's co-authors and a stalwart of the Bridge Line Historical Society, which cooperated in the production of the book) of no fewer than 15 of them ready to be sent to the D&H from Bethlehem Steel's Johnstown, PA plant, which had rebuilt them in 1967. The caption states that 250 cars were part of that program: D&H 9401-9650. On the same page is a photo of the 9522 in 1974, with most of the red paint obscured by black. On page 74 a photo shows one red car with so much rust on its sides that its number can't be seen, plus 9471 as repainted by the D&H's car shop at Oneonta in 1971: also oxide red, but with a billboard road name as first used c. 1954-1956.
Two mineral products were shipped from the NL Industries (originally National Lead Company) plant at Tahawus. Most cars carried ilmenite (titanium ore) to processing plants in northern New Jersey and in Missouri. This was used to produce not just titanium metal but also titanium dioxide, a white pigment that NL used in Dutch Boy paint. The irony is that ilmenite itself is VERY black and made the cars that carried it very dirty very quickly. I visited the mine in 1971 with my fiancee (to whom I'm still married). One of her aunts owned anI have inn in Newcomb, the closest settlement on a numbered state highway. In the laundry across the street were big signs: NO MINE CLOTHES. I need to dig out a slide I had her take showing me next to two yellow ribbed twin hoppers (built by Bethlehem for the D&H in the 1960's, clearly labeled "ilmenite loading only"), one clean and the other unbelievably dirty. What a contrast! Decades later I corresponded with a man who worked at the NL plant in New Jersey. The crew at the diner he often visited were mystified by his appearance. They were used to seeing workers in blackened clothes who worked at the start of the production line and ones covered in white from the other end of it. He worked sometimes at one end, sometimes at the other.
Iron ore (magnetite, I think) was separated at the Tahawus plant, sintered, and shipped in open hopper cars. The heat burned the paint off the sides of the cars, which became rusty. I'm not sure where it went, but when the shipments started when the line was extended from North Creek to Tahawus (or Sanford Lake) during World War II, it probably went to Republic Steel in South Troy, NY. These cars were outnumbered by the ones carrying ilmenite. For a long time older steel hoppers were used to carry the sinter. The D&H bought some new. larger cars and gave them minimal paint, with the most essential lettering on separate steel panels welded to their ribs. (The ilmenite hoppers had similar panels though their paint didn't burn off. Guilford transferred many of these cars to the Maine Central before letting the D&H go bankrupt; many are still in non-revenue service and the original lettering on some is still visible under decades of grime.)
HO models of the oxide red cars as done by Bethlehem in 1967 have been done by two firms. Decades ago Third Rail Graphics decorated three Athearn cars. Atlas has produced models with even nicer lettering, with the gaps in the letters from the stenciling! A new Atlas HO run including two single cars and a three-pack with new car numbers is expected to arrive this quarter, plus, for the first time, similar cars in Nn scale.
