I am trying to figure out the correct rollers to fit into this existing track
Please see the images provided it is a low-profile track and will most likely be either of these parts you have. the inside track is approx. 7/8"
https://www.swisco.com/four-wheel-wardrobe-roller-and-bracket/pd/Pocket-Closet-Door-Replacement-Hardware/23-193
https://www.swisco.com/Pocket-Door-Roller/pd/Pocket-Closet-Door-Replacement-Hardware/23-138
please advise