Yes, your Plymouth had inner grease seals too. It's common for folks to reuse grease seals, but it never hurts to replace them. You typically have to pry them out to get out the inner wheel bearing.
You should clean and pack the bearings, and use a high temperature grease. A good molybdenum disulphide gun grease will work well. But it has to be capable of taking the heat. The old honey colored grease is typically not up to the task.
Pack the individual bearings well, and add grease insided the hub all around level with the imaginary line between the inside diameter of the races.
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in