fwiw,
I had the CS prop on my plane overhauled the first week in January. A few of issues prompted me to get it overhauled even though it only had ~300 hrs on it when I purchased the plane in September. The main driver was Hartzell recommends a 60 month TBO for this propeller and it was past that point on the calendar. It is a Hartzell 2-bladed prop. Also, because it has a steel hub it is subject to a 500 hr AD for corrosion inspection. Another reason for getting the OH was I felt there was an unusual amount of vibration related to engine speed, confirmed by an attempt to balance it dynamically. After the prop was in the shop it was determined that the blade clamps were mismatched by the previous overhaul facility in 2000. Any time you buy a plane you better be prepared for a few surprises, despite how thorough your pre-buy is.
Hartzell aluminum hubs are not subject to that AD per the tech staff at Hartzell. I had called them to inquire about the possibility of changing to a 3-bladed prop. They sent me a list of "allowed" blade/hub configurations for various engines and there was one listed for my IO-540. A new 3-blade was going to run $12k-$14k, so I opted to overhaul this go round. If the prop ever becomes unserviceable (the blades on mine are rather unique, lead time to fabricate new ones is 14 weeks), I still might go 3-bladed, or at least go with an aluminum 2-bladed hub to avoid the 500 hr AD. We'll see where we are in 500 hrs.
I got several quotes before I decided on R and D Propeller in Pearland, TX, ranging from $1200 to $3000 for an overhaul. Special parts extra. The low end was basically disassemble, inspect, and reassemble. The high end included the basic inspection plus replacing all parts recommended by Hartzell (no reuse of threaded fasteners, etc.). Mine ran $3900 which included $1600 for new hub clamps. The old clamps could not be reused per Hartzell instructions. I was skeptical that I was being sold some snake oil, but after I got the prop back it didn't require any re-balancing to be within allowable limits when we checked vibration levels after installation. And the prop response during run-up is much smoother now.
I am very satisfied with the work done by R and D Propeller. Prop condition is often overlooked imho, considering it's probably the most highly stressed component on the plane (except possibly the crank, or the pilot, who some consider to be a crank), I feel I have a small measure of assurance that the one on my plane is in as good a condition now as can be reasonably expected.
Attached is Hartzell's recommendations on TBO.