See if this link comes up -- are these the exact drivers you are referring to? The Seas 27TFFC (H881) as a tweeter replacement and the 25F-EW (H085) woofer? They're what Madisound recommends as the Seas replacements for the A25 (for what it's worth -- the majority consensus over at Audio Asylum was in favor of the Seas 27TFFC versus the Morel.. but both seem to please folks).
If I can just use my boxes and the aperiodic vent, that would be a worthwhile project. I may be calling Madisound soon to do a little digging.
cheer, marc