Ahhh...but the diescast collet noses are often prone to breaking. And when that happens, there really isn't a quick fix.
When I placed my order for a New Rogers set in 1974 I discovered after receiving them that the diecast collet noses were weak. My 'fix' was to get some of the old machined units to replace the diecast ones. I put the original diecast in storage and from then on used the machined units which protected the diecasts from the typical cracking at the ends and breaking off of the 'ears'. When the time comes to sell the set, the new owner gets both styles.