This picture shows three different versions of the MS150 speaker (the one on the far right is actually an MS150.2). All three are in need of new foam surrounds on the woofers.
Here is the first set, a first generation MS150 in need of repair.
The two woofers (8 inch and 10 inch) need to be removed and the surrounds replaced.
Here are the replacement surrounds and cross-over capacitors.