Looks like that "gift" car is going to get expensive fast...
In vintage Mbz parlance, the 300td is the "estate" wagon, and the 300dt is the sedan. Do you have the wagon?
Unless your car is a grey market version, it most likely already has a turbo on it. Did you look under the hood?
1984 300D with Monark nozzles, GT2256V w/ Synkooppi/Arduino controller, W123 n/a intake, air/water intercooler, precup holes reamed, IP & valve timing = fac + 2 degrees, upgraded leather interior, 140A alternator, electric lift pump, 3" aluminum radiator w/ electric fan, HID headlight conversion, bilsteins, stock MW IP turned up 3 turns on tq module per OM616, 2.65 rear end, ventilated front rotors, dual rear swaybar mod + W116 springs -
https://www.youtube.com/watch?v=4zPSyCMkkk0