I think maybe some people are misinterpreting OP's question. If what you are talking about is accruing more seals, then here's the plan my linkshell mates and I have more or less been going with.

- Do Toto-Rak and the Darkhold while having the quest open to get 4000 seals or so in a city.
- Pick the weapon (r50 weaps seem to be the obvious choice).
- Start it again and do it in a different city, get next weapon of choice.
- Repeat a final time

Obviously the flaw in this is that you need to be 45+ to clear Darkhold, but seeing as how you're 50 CON I think you can handle it ^^

I've been going on the assumption that once 1.19 comes out and you have more options than "recruit", you're going to be locked into a certain city-state once you progress. Obviously this would not allow for all the weapons to be obtained.

Please note that this is pretty much conjecture, but it seems semi-logical.

edit: After re-reading the OP, I'm not even sure if I understand it. I hope this helps.