You listed the model number for the mower. You need the MODEL and TYPE numbers from the engine itself. It’s usually located on the recoil cover just forward of the muffler, stamped into the metal. With the correct numbers, contact Power Distributors for the replacement engine.
Check to make sure the float in the carb is level when held upside down. Sometimes the needle/seat swell and causes inadequate fuel flow to keep up with demand.
Your choke butterfly valve is not closing completely when the actuating lever is in full choke position. Needs a tweaking to be completely closed for cold start.
I’ve never seen aluminum grass and why would you want to catch it anyway unless you plan to recycle it since aluminum prices are up. Ha-ha, but seriously each grass catcher is made for a specific unit. I’ve never seen aftermarket grass catchers. Look on Craigslist or Facebook marketplace for...
The difference between a reputable dealer and the big-box-stores is the initial set up.
The dealer will take the time to level the deck, adjust the controls, etc. and make sure the unit is ready to perform.
The bolt pattern on the wheels may be different between the two manufacturers. Measure the mounting bolts center-to-center. Also, the set back on the wheels may be different, causing rubbing against the frame if not correctly sized.