A piece of equipment that was purchased $2$ years ago by Toshiba Imaging for $$50,000$ was expected to have a useful life of $5$ years with a $$5000$ salvage value. Its performance was less than expected, and it was upgraded for $$20,000$ one year ago. Increased demand now requires that the equipment be upgraded again for another $$16,000$ so that it can be used for $3$ more years. If upgraded, its M&O costs will be $$22,000$ and it will have a $$11,500$ salvage after $3$ years. Alternatively, it can be replaced with new equipment priced at $$65,000$ with M&O costs of $$14,000$ per year and a salvage value of $$23,000$ after $6$ years. If replaced now, the existing equipment will be sold for $$7000.$ Determine the values of $P,S,M$&$O,$ and $n$ for the defender in a replacement study.

The value of $P$ is $$-$

The value of $S$ is $ $$

The value of M&O is $$-$ per year.

The value of $n$ is $$ years.