The 30GT was the Glenfield variation of the 336 Texan. Should have the straight stock. Your gun was made in 1979. Value, depending on condition, would be $250-$300. sales@countrygunsmith.net You can try to see if this manual here would work for parts breakdown (see page 13 and 14) - http://www.marlinfirearms.com/pdfs/manuals/MFC_Centerfire.pdf
Your Glenfield Model 30GT is basically a Marlin 336 with a straight stock. If you go to Marlin firearms website you can download the manual there. Your 30GT was only made in 1979 and 1980 then discontinued. The T stood for Texan the G either Glenfield or Grand depending on who you talk to. Based on the 21 in the serial number (oldguns.net) your 30GT and mine were made in 1979. They were not as poular due to the difference in the stock design and only 7,737 were ever made. About $250 is a close estimate on value. They are excellent shooter, just not collectible even though rare.
The Mariner web site is probably the best resource for information about their products, including manuals. Sites such as MarineEngine and FilesTube have the manuals available for download as well.
You might be able to find some online, but Bobcat does not officially license any service documentation for free distribution. Unlike many other manufacturers, Bobcat also does not make parts information available for download. You can purchase their manuals and other information online at bobcat.com/service-maintenance/manuals.
Since it is proprietary information...you will have to buy it...:-( ...either from John Deere or I&T manuals
You can go to Lincoln.com and download all manuals. Just click on the "Owners" tab and create an account. You can go to Lincoln.com and download all manuals. Just click on the "Owners" tab and create an account.
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You can download the workshop manuals for 1964 Renault 8 year on repairservicemanuals.com/Renault/8 Gordini/1964/