Cat 60 prices

Hello gang: Friends here regularly suggest that I broaden my collection of toys. This one is calling me.
It will never be a runner, and it doesn't take up much room considering it's a SIXTY.
Could someone tell me what the original retail price was supposed to be, and current market prices if any?
Any specifications? The Diamond set in it, how many carats originally? How many built?
This thing is very heavily built as well. Trying to figure out how many ounces of precious metals went into it.
I likely will buy a large gun safe to house it. 
Thanks, JM

Similar???

https://www.christies.com/en/lot/lot-5950321

Limited Edition 500 made in 1991

http://justacarguy.blogspot.com/2015/12/caterpillar-sixty-silver-and-gold.html
 

JM, find a 4FB D8L - I'm SURE you need that in your collection - just right for pulling those (gee)agricultural implements....I'll go you halves : )

Hi Team,
back in the day I was given the envelope and contents of the package sent to William Adams the local Cat Dealer I worked for by Sales Guides Inc. who were commissioned by Caterpillar to handle this model and offer it to Dealerships first.
The letter is dated Jan 22 1990.
The model is museum quality, came in a cherry wood and glass display case and cost a total of US $5,900 for each of the 500 units offered.
It weighed some 25 pounds and consisted of one troy pound of silver, solid pewter and brass with gold embellishments of 24-karat gold, it is topped of by a full-cut diamond on the radiator cap. Is made up of some 300 individual pieces, polished and assembled by hand.

Cheers,
Eddie B.
The model is approximately a 1:12 replica so is 12.75" long by 7.3" wide.