There were so few '03s in comparison.
Here are the part numbers and I checked, the clutch master cylinders are all the same, the brake master cylinders are specific to the '03 (IIRC, smaller front disc size, also). This might help you in your search for used parts. MAYBE you can use the newer brake cylinder on your '03. Remember that the '04-'05 had optional ABS and those master cylinders are a different number.
'03 front brake master cyl: 5DM-W2587-01-00
'03 clutch master cylinder: 5JW-W2645-01-0
'04 front brake master cyl: 5JW-W2587-00-00
'04-'05 clutch master cylinder: 5JW-W2645-01-00
'05 front brake master cyl: 5JW-W2587-00-00
'05 clutch master cylinder: 5JW-W2645-01-00
In the FAQ section you'll find
this thread. Make a few inquiries and see who has the best price for your parts.