Changing a weapon into a different weapon?

[Zathyr]

So I have a character with a non-magical adamantine longsword. For reasons many can probably guess, I would prefer it to be a scimitar. What suggestions are there for doing this? It doesn't seem to me like it should be too difficult or expensive or an unreasonable thing to do. Adamantine could be hard to work with. Yes, I know, talk to my GM, but I was just curious about what feedback I could get here first. There could be something RAW and simple I've overlooked.

I suppose I could use the crafting rules to make an adamantine scimitar and use the longsword to cover the cost of materials, but that's going to take a lot of time. Would it be reasonable to say that since the masterwork component is generally crafted separately, and an adamantine weapon includes the cost of being masterwork, that the masterwork/adamantine "component" of the weapon is already made and just use the DC 15 for a martial weapon and ignore the cost?

For 1,125gp I could grab a scroll of Fabricate to possibly speed up the process. Longsword and scimitar both weigh 4 pounds. I'm not sure if/how the associated craft check comes into play here. Still more than I'd like to pay.

I could make it magical (which I'd like to do anyway) and add the transformative property, but that's really cost-prohibitive and not terribly useful beyond making it the scimitar I'd like. If it could turn into light weapons I might consider it as an option down the line, but as it is, meh.

Other options?

[Orfamay Quest]

Dervish dance, huh?

Under strict RAW, the most straightforward way to do it is to hire a caster for the fabricate spell. 5th level spell, 9th level caster, 10 gp per level, is 450 gp. A simple scroll or potion of crafter's fortune should help with the crafting roll.

Aside from that,... I would probably rule that the cost of adamantine weapons incorporates in part the working of the adamantine as well as the cost of the adamantine ingots. Supplying worked adamantine in the form of a longsword doesn't make it any easier to work. (As Pathfinderwiki puts it, "Manipulating the metal requires special forges capable of reaching extreme temperatures due to its high melting point. And those forges aren't cheap.) I don't know any source for the price of unworked metallic adamantine, but the fact that a 1 pound adamantine dagger costs roughly the same as the 8 pound greatsword or the 12 pound halberd suggests that most of the cost is labor....