Custom Spoke head height

So I’ll admit I’m a tad in over my head on a project I’m working on. It’s a 67 Yamaha U5E scooter which I am aware isn’t this forum’s specialty, however, I’ve seen the massive collective pool of knowledge yall have. I have been attempting to rebuild its front wheel and am having trouble sourcing the correct spoke. The ones I require have a longer head height (distance from top of the head to spoke centerline) than what is commonly sold. I bought a set for a similar model that was supposedly compatible but wasn’t. I think I’ve got a couple options and was wondering your thoughts on it. 

1. Buy custom spokes from some website. I’m not exactly a fan of the prices I see on buchanan’s so are there any other options? Or are there any 12g spokes you know of that have a head height around 8-8.5mm? I only need 18. No I can’t find any replacements for the model as it’s decently rare.
2. Bastardize my current wheel center by cutting a 1-2mm grove where each spoke needs to go. This would allow me to use the entire spoke set I bought. I don’t think it should weaken the wheel center much at all as the part I’d be cutting away shouldn’t be providing much structural rigidity. I feel bad about it but this is the way I’m leaning at the moment.
3. Probably very unlikely but I may be able to find the hub for the very similar bike and use that instead. I can’t find any on eBay at the moment.

the pictures I’ve attached are of the wear marks from the original spokes as well as the a picture of one of the old spokes and new spokes put into the hubAny and all input is appreciated!

I ran into this same problem when i bought some cheap Thai spokes for a KZ650. I just bent them a little more and it worked fine. The spokes are in tension so it wont matter at all. I think I put 30k miles on those wheels. you can make a simple 3 post bender using some boards and some lag bolts.
 

If you still have some of the spokes you removed Devon Rims make spokes from using the old ones as patterns. 
A mate of mine is a spoked wheel rebuilder and if he comes across any trouble sourcing the correct fit he gets Devon Rims to replicate them in stainless. 
They are in the UK but ship world wide or you will likely have someone offering the same service in your country. 
There is not any additional costs involved, barring postage, as they see it as adding the spec info to their library for future reference. 
He had the same issue re kz650 spokes as DoctoRot had  and sent Devon Rims some off the old ones to copy. 

www.devonrimcompany.com/