The model and serial tag is missing, and it has a replacement 8HP Briggs on it. I am trying to figure out what model it is so I can get the correct parts manual. It has hard rubber front tires, and the early metal rounded gas tank. Blade is 28" long. Also has the rectangular handle.
Your Snapper Comet riding mower is a 30" cut model. ....If it has a 28" blade, it has the wrong blade on it.
Snappers were made in 25", 26" 28", 30", 41" and 42" cuttting widths over the years. .....The 25" mower was the only model to use semi-pneumatic ("hard rubber") tires. ....All the others had 4.10-3.50 x 4" pneumatic front tires.
The 25", 26" and early 30" models used 4.80/4.00-8 rear tires. ....Later-model 30" mowers and the others used 16-6.50 x 8" rear tires.
25" and 28" mowers were Hi-Vac models. ......The 41" and 42" mowers had multiple blades while the 25", 26", 28" and 30" used a single blade. .....For best bagging results, the Hi-Vac models were better than the others. ....However, the non-Hi-Vac models do a better job of spreading the clippings if bagging is not a priority. .....There were air-lift extensions which could be bolted to the single blades to improve the bagging performance.
I would guess that your mower is a Snapper Comet model 307X or 308X, from the 1970's. .....Both of these models had the wide rear tires and loop-style steering handle. ....The 307X had a 7hp B&S engine, while the 308X had an 8 hp B&S engine. (The first four numbers of the B&S Code number will indicate date of manufacture. ...It's possible that your engine is the original engine.) ......B&S model 170702 was 7hp, while B&S model 190702 was the 8hp.
(By the way, your steering handle is mounted incorrectly. .....Remove the bolts and turn it 180*. .....This will prevent the steering handle from hitting your knees when making turns.) ....The seat pan could be mounted in different holes to adjust the seating position.
Snapper riders used mostly B&S engines, but Tecumseh engines were also used on some models. ....The 41" mower had a Wisconsin engine.