How close do you need to be?
Since you are using 5% resistors, do you have a way of measuring the resistors with more accuracy than that? Or, with whatever accuracy you need?
If you have a way of accurately measuring resistance, you can select two values that add closest to 450.21 and wire them in series.
If you can’t measure the resistors accurately, you can’t be guaranteed of being any closer than 5%.
25 Ohm 50 Ohm pot would give you 5% adjustability. A 10-turn pot would probably give you the precision-adjustment you need. (Actually, you’ll need about 50 Ohms for a little more than +/-5%, and remember that a pot in series will add to the resistance, so the other 1 or 2 resistors should add to less than 450 Ohms.)
Selecting resistors (or other components) usually isn’t good engineering practice because it’s difficult to reproduce the circuit. You end-up scrapping lots of parts and you may buy 100 parts and not find any usable parts.