Further research makes me believe that Bolens never manufactured the # 18907 sleeve hitch, but instead they were made by Brinly.
Bolens assigned # 18907 to the Brinly model # HH-106 Sleeve Hitch
Bolens assigned # 18908 to the Brinly model # PP-508 8" Moldboard Plow
Bolens assigned # 18910 to the Brinly model # PP-510 10" Moldboard Plow
Bolens assigned # 18911 to the Brinly model # PP-512 12" Moldboard Plow
Bolens assigned # 18923 to the Brinly model # CC-500 Cultivator
Bolens assigned # 18955 to the Brinly model # DD-100 (?) 8-Blade Disc Harrow
The Brinly Dump Cart for tube-frames was known as Brinly model # BB-110, and did not carry a Bolens part number (as far as I know)
All of these attachments and the hitch were painted Brinly white with the black/white Brinly decal.
It is probable that the red Ohio Steel sleeve hitches were obtained by dealers or supplied through distributors, but not through Bolens.