The tubes have never been used in anything other than a Grade 6 Citori. I would think they should work in a 525 Citori but I don't know for sure. As long as your choke fits over the tubes you should be okay, may have to use a modified or something other than a full. I've use other tubes in a gun with ported barrels and it made no difference.
If the tubes need fitting to your barrel I will give you a name of a stock maker/machinist friend at Linn Creek, MO. where you can send your barrels and the tubes for free fitting (you pay shipping both ways).
If you would've answered post #2 that would let guys know what Browning guns they will fit without having to either have them 'turned down' or 'built up'.
Older Citoris are Invector and the newer guns (1990 ? and newer) are Invector Plus.
They DO NOT share the same internal bore dimensions...
Briley does not warranty tubes when the original owner sells the set unless you as the new owner do a transfer warranty and pay a fee between 100 and 200. I bought a 3 gauge set and one 20 ga tube developed a small crack along the ejector cut out. Because I did not transfer the warranty I was not eligible to have the tube repaired under the original warranty.
I also bought the gun the tubes were fitted to so my guess is there would be no warranty available if fitted tubes were used in a different gun. Best to check with Briley what they would do in that situation for fitted tubes.