Can frankens really be considered rare reps? I feel that since they're not exactly a production item, it's not exactly fair to categorize them in the same sense of distinction...
A few of my personal favorites that I've built, owned or have owned, etc...
16520's with El Primero 400s
DW 6263 franken with Swiss V23 transplanted
FrankenDJ built from a genuine case, dial and ETA
Franken Tudor built from an old 1680
Franken Radiomir built from an old 183 case and watchmaster dial
A very old self made PAM4; PVD work from IWW with a nice Dirk fitted
An old TW Best Omega Constellation with skeletonized ETA 2892
'Old Factory' Ti Seawolf with 2824 and genuine dial installed
And, perhaps the 'rarest' of the frankens? Might not see another one of these (but for good reason )
I've built a number of others, but these seem to be the ones that stand out most to my recollection. Some of those have gone on to other homes... I miss them (and oft times wish I didn't let them go).
Have some more projects for '08; some are near completion and some are still in conception. Enough to keep me busy for a few months...