My experience, FWIW:
The actual chokes in both my Huglu .410s were different from the chokes marked on the barrels (and what I thought I was getting). The SST gun (photos in earlier thread) was marked IM/F and was actually way beyond full in both barrels. The other Huglu .410 was marked IC/M and gauged out at F/ExtraF. Just saying don't be surprised when you check the chokes in your new .410.
I use Briley if I think the gun is going to need thin wall choke tubes (common on Spanish side lock light to medium game guns). Otherwise I send guns that need to have choke tubes installed to Colonial Arms. Colonial has put choke tubes in .410s (5), 28 ga (1), 20 gauge (5 - soon to be 6 as they are putting tubes in a 20 gauge Urbiola right now) and 16 gauge (3) guns for me, using their own brand of choke tubes. I've always been completely happy with their work and ordering additional tubes is a breeze.
At one time I used Mike Orlen but his work became so problematical that I stopped sending him any work.