I also bound my own 110 and have been training up (109.3 now). I have been getting dungeon fish requests now, and with those it's possible to get up to 180 weight on a 6-part order. There is one very nice bonus when you get past 106 fishing and dungeon fish are included; I've noticed that since there are more things that can be included in an order, the chances of having crab/lobster is reduced. Having crab/lobster worth .5 is just crazy stupid.
Dungeon fishing is actually my favorite for kick-back relaxed fishing. When I fish, I sometimes like to put on a movie or something, then just press a button on my UO computer every few seconds and fish. However, sometimes fishing deep water you drag up a sea serpent, which is cool to get MiBs and nets, but not cool when you're leaning back in your chair with your feet up and a cool beverage in your hand. All of a sudden, sea serpent, mad scramble for the keyboard, spillage everywhere

. When fishing in dungeon you don't get sea serpents, and there are plenty of spots that are basically completely safe, and now you get the added bonus of 1.5x points. It adds up quick in the quest orders.
I'm just going to speculate here. The maximum possible points per order is 180 (6-lines, with 20 fish per line, and at 1.5 points 30 points possible per line). I'm going to guess you need about 100 points minimum to have a shot at a 110 scroll, 130 minimum to have a shot at a 115, and 160 minimum to have a shot at a 120. I think I've only had one order valued at 100 or higher (got 100 units of king fish bait), but haven't been doing as many quests since reaching 106 fishing. I will again after getting to 110 (hopefully soon). Let's just say orders valued at 150 or 160 points will be extremely rare (6 lines, almost all 20s and all but one or maybe two for dungeon fish).
One final thing. When talking to Mesanna I mentioned that I don't think anyone on any shard has reported receiving a PS higher than 105. Her response was that the person who designed fishing thought it should be hard, but it should be impossible; so perhaps they will tweak it in the future. I'm glad that everyone can't get to 120 fishing a week after release, but would like to know there's a realistic shot at higher PS without and endless grind.