Did some of the 4500s come with Boxpok drivers from Baldwin? I have only seen 4500s with Baldwin universal disc drivers.
Any pictures showing the rest of us what they look like? Really just looking for more steam locomotive images.
Here is a link to an on-line article about drivers that explains the differences. https://www.steamlocomotive.com/types/drivers/ It has a link to a Boxpok driver with spoke wheels on the same locomotive for comparison. https://www.steamlocomotive.com/whyte/4-6-2/USA/photos/bm3659-weber.jpg There is a prime example of a Baldwin disk driver as fitted to 4-8-4 SLSF 4500-4514 for comparison at this link. https://www.steamlocomotive.com/whyte/4-8-4/USA/photos/slsf4500-barris1.jpg Another sterling example of Boxpok is at this location. http://www.frisco.org/shipit/index.php?threads/4525.13386/ If I recall, there was a diagram of a Boxpok driver on Frisco.org somewhere.