Lear, you missed a very important word in the original posting "CHARTER". Looking cool has nothing to do with being a viable charter operator. There are many reasons why I recommend that a Lear 20 series Not be in the picture. One is noise. The hush kit is fine but will the Australian FAA (CASA) accept it? Two is the age of the aircraft. As aircraft become older they become less reliable. And one thing that is extremely important to a charter operator is reliability. Three fuel burn. Fuel costs here in the States is bad enough. There it is a heart attack. Availability and cost of parts. I'm running two 25's right now and I am having a hell of a time getting acceptable parts and I'm here in the States. Engine overhauls are getting out of hand. I paid almost $350,000 for my last one almost three years ago. I have heard that they are running $450,000 plus depending on how many wheels you have to replace.
I do not recommend any charter operator even look at a 23. It is a wasted effort. I had one offered to me late last year. I turned it down. Trying very hard to get out of Lear 20's altogether. One will be leaving shortly, being replaced by a Westeind 2. The other, the owner loves it like you love the 23's. He'll probabily be buried in it.
The charter business is just that a business. And it needs to be treated that way.