I know there isn't anything special about a factory one, but I just want one.  Thanks for responding.
		
		
	 
You want a REAL factory one?  It's not even made by John Deere.  Your tractor is just a Yanmar painted JD green.  Yanmar has made Compact tractors for JD for the past 40+ years.  Your 790 was made in Japan.
With all that said, it's easy to get an OE top-link (aka center-link) for the JD790 from a Yanmar parts distributor without the Deere high price markup. 
HOYE has your part here for a mere $20:
TOP LINK: Yanmar Tractor Parts 
Fredricks has your part too for $20: 
Top link - TL-111 - Fredricks Equipment Parts - Your home for Yanmar, Mahindra, and Bad Boy Mower parts! 
Both match the image 'beenthere' posted. 
FREDRICKS EQUIPMENT
1312 South Bethel Rd.
Decatur, AL 35603
PARTS HOTLINE - 256-751-3555
email - 
parts@fredricksequipment.com
NEW On-Line SHOPPING - 
Shop - Fredricks Equipment Parts - Your home for Yanmar, Mahindra, and Bad Boy Mower parts!
Yanmar; YM / FX / F / Ke, John Deere / Kubota / Iseki / Mahindra / Others 
HOYE TRACTOR PARTS INC.
2099 US Hwy 287 E
Iowa Park, TX 76367
PARTS HOTLINE - 940-592-0181
Contact page - 
Yanmar Tractor Parts:
On-Line Shopping - 
Yanmar Tractor Parts:
Yanmar Parts / John Deere / Yanmar Marine engine parts
SOUTHERN GLOBAL
404 First Street North
Wiggins, MS 39577
PARTS HOTLINE - 866-742-5748  Toll Free
email - 
sales@southern-global.com
On-Line Shopping - 
https://www.southern-global.com
New parts for Yanmar / John Deere / Others
Japan Tractor Salvage Yard
Engine overhaul/rebuild kits
STEVENS TRACTOR PARTS
3715 Highway 71
Coushatta, LA 71019
PARTS HOTLINE - 800-333-9143  Toll Free
email - 
sales@stevenstractor.com
On-Line Shopping - 
https://www.stevenstractor.com
Japanese and Domestic Tractor Parts for many makes and model brands
Engine overhaul/rebuild kits
WEAVER'S COMPACT TRACTOR
22 Fish Hatchery Rd
Shippensburg PA 17257
PARTS HOTLINE - 717-477-9332
On-Line Shopping - 
https://www.compactractorparts.com
Japanese and Domestic Tractor Parts for many makes and model brands
ALL STATES AG PARTS
10 Ellefson Dr
De Soto, IA 50069
email - 
support@tractorpartsasap.com
PARTS HOTLINE - 866-609-1260  Toll Free
On-Line Shopping - 
https://www.tractorpartsasap.com
13 Locations for tractors and parts, 10 salvage yards, and 2 repair centers all in the Mid-West
Japanese and Domestic Tractor Parts for many makes and model brands
SHEAFFER'S TOWN & COUNTRY TRACTORS INC.
320 Palmyra Rd
Dixon, IL 61021
PARTS HOTLINE - 815-284-3226
email - 
parts@sheftractor.net
On-Line Shopping - 
https://www.japanesetractorparts.com
Japanese and Domestic Tractor Parts for many makes and model brands
TRACTOR JOE PARTS
14385 23 Ave N
Plymouth, MN 55447
PARTS HOTLINE - 888-860-9096  Toll Free
On-Line Shopping - 
https://www.tractorjoe.com/yanmar
Strong Yanmar Gray Market parts provider
Offers a comprehensive selection of equipment and parts for US Yanmar & Yanmar Gray Market tractors