Balancers
These are Series 380 or Series 385 channel balances. See which shoe you have, shown below. The 1" shoe means you need S380-34 and the 1-3/32" shoe means you need S385-34. These balances are offered in a 3340 option like your old balance.
The part numbers for the plastic pieces are actually irrelevant, they're just used to identify the balance that uses those attachments. The bottom attachment determines which of these two Series you need, and the top attachment is standard. Just measure and choose one or the other.
If the black "sash guides" are in good shape, they do not need to be replaced. If they are broken, remove them from the window and send photos.