The FSM is prone to typos. Very prone.
ASA lists the following for low and economical lines of the C52a base model, solid front rotor brake setup:
1988.04.1 to 1990.05.3 MB366435 Superceded to MB316676 13" (I suspect that is in fact 13mm thickness solid)
1990.06.1 to 1992.04.3 MB618737 Superceded to MB618736 13" (same thing about rotor thickness, non-vented style, captive)
I always thought the stock brakes were in the 238mm diameter range, but that is the MI238 number that sticks in my head for rotors from Brembo.
Here are listings from Ferodo and Brembo from 1990.06.1 listed with Rockauto:
FERODO Part # DDF947 {#MB618736, MB618737} Diameter [mm]: 234; Brake Disc Thickness [mm]: 13; Minimum Thickness [mm]: 11.4; Centering Diameter [mm]: 86; Number of Holes: 4; Height [mm]: 34; Sold In Pairs
Flag indicates this part fits vehicles sold in the European Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Front Axle
BREMBO Part # 08707210 {#25198, MB618737}
Flag indicates this part fits vehicles sold in the European Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Front; solid disc; 05/90 on [Wholesaler Closeout -- 30 Day Warranty] (Only 12 Remaining)
Not sure if the site is wholy accurate or not, but multiple listings for the same Mitsu number and same rotor diameter.
Whatever rotor you get, it has to match the exact diameter of the old rotor. Place the rotors back to back, contact surface to hat, hat to contact surface to confirm the offset of the hat is identical too. I see cheap white box parts and I've seen some serious alignment and fitment issues. If your rotor barely clears now, what happens when it rusts?