https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/mtd/mtd-legacy-1985-2005/mtd/13-lawn-tractors
Above is the list of 1995 MTD tractors and if the engine is original then you have a 1995 or 1996 model.
Now measure your deck with of cut,
The last letter in the model numbers listed on the site above is the deck size & type.
They code out as follows
Deck Identification
Cutting Deck Size
A 30 in. Rear Discharge Hard Top Catcher
C 30 in. Rear Discharge Soft Top Catcher
D 32 in. Side Discharge
E 36 in. Side Discharge
F 38 in. Side Discharge
G 42 in. Side Discharge
H 46 in. Side Discharge
N 40 in. Rear Discharge
P 50 in. Side Discharge
This will cut down the number of models for you to check till you find the one that looks like yours.
Alternatively you can take the blades off and check the part number on the blade.
Drop that into the Jacks web site and it will bring up a list of models those blade were fitted to.
A couple of photos of the complete machine might allow some members to recognise the mower.