First of all,:MTF_wel2:. You've come to the right place for info and help. There are alot of knowledgable guys here that can answer your every question.
To answer your first question: Here is a link to oldgravelys.net. There is alot of great info for the Gravely owner/enthusiast. This link will give you info on identifying your tractor.
http://www.oldgravelys.net/pdf/Cust_Serv_Update_88_89_1188.pdf
As for the manual, here is a link to a page that you should be able to find a manual for once you have identified the tractor you have.
http://oldgravelys.net/docs/walkers/
Good luck. I'm sure somone will be along to supplement this information with their own good advice and info.
To answer your first question: Here is a link to oldgravelys.net. There is alot of great info for the Gravely owner/enthusiast. This link will give you info on identifying your tractor.
http://www.oldgravelys.net/pdf/Cust_Serv_Update_88_89_1188.pdf
As for the manual, here is a link to a page that you should be able to find a manual for once you have identified the tractor you have.
http://oldgravelys.net/docs/walkers/
Good luck. I'm sure somone will be along to supplement this information with their own good advice and info.