Hi Alan,
I suspect that's not the original speaker. Looking at the database on the Yahoo Hacker group, that serial number is either late RP25 or early RP25A - meaning that either the later Goodmans speaker with no bolts should have been fitted, or, more likely, a silver Celestion. I've got two RP25s with earlier serial numbers (27794, 28560) that have the later Goodmans speaker, and my early RP25 with your speaker is 08259.
For what it's worth, all 3 of my Celestion speakers have rubbing voicecoils to varying degrees. Are they less reliable than the Goodmans? I've got many of the Goodmans speakers in all versions, and they all work perfectly.
Regarding the bass, it's worth running through the amplifier checks in the service manual, which will eliminate any problems with aged capacitors. But, Hacker didn't attempt to produce a bloated bass end, preferring instead to achieve a smooth, non-resonant sound that was more akin to hi-fi (obviously not as extended). That contrasts sharply with the Grundig set I'm working on at the moment, where the excessive amounts of bass boost combine with the plastic case to produce a bass-heavy sound that is initially impressive, and fine for background use, but quickly becomes tiring when listened to critically.
Also, check the impedance - if it came from an earlier set (e.g. RP10, RP18, RP30/31/32), it might be 30 ohms.
Thanks,
Mark
