You're in luck. The MB has a drain on the torque converter. This should be an easy DIY for under $40. I believe your transmission is spec'd for Dexron II and you can use Dexron III. You'll have to rotate the engine to find the torque converter drain plug. Without going into too much detail... Drain both the pan and torque converter. Change the filter. Refill with the same amount (~7 qts?). When refilling, put in only 4 qts, then start the engine and add the remaining amount. Refill it shy about a quart so you can measure the fluid level warm after a long drive.

Differential... remove the fill plug FIRST!! If you remove the drain plug and can't refill it, you're in deep doo-doo. I recommend using synthetic fluid such as Mobil 1 75W-90. Buy two quarts. It'll take a bit more than one quart to refill it.

You can check the motor mounts by opening the hood and watch for motor movement when you shift back and forth between Drive and Reverse.

Since the car is new to you, check the rest of the fluids and filters. Consider replacing the fuel filter, steering fluid filter, and replacing the brake fluid, steering fluid, and coolant.

Do a search on these topics, you'll get lots of well written discussion and details on these projects.

__________________
95 E320 Cabriolet, 169K