Impossible to answer without a serial number.
@ 39 yrs old
@ 49 years old
Standard Catalog of Smith and Wesson, 3rd ed.
45 yrs old
Your serial number indicates that your Smith and Wesson model 29 was made between 1977-1978.
What serial?
33-34 years old
@ 1980
100-1000 USD
1994
The Model 29 is a 44 Magnum.
You need to find a copy of The Standard Catalog of Smith and Wesson, 3rd edition by Supica and Nahas. The Model 29 and it's variants take up a couple of pages.