I can't tell you how many times that I've done something similar....read below:

Problem
When I was setting up my front aluminum hubs for new brakes, the tanged washer for the wheel bearings was too large in diameter.
Had to reduce the diameter for it to fit.

Solution
I made my own mandrel, 10 hours, after all the washer must not slip while cutting down the diameter.
Then... cut the metal down, for a perfect fit (x2, both sides, 2-1/2 hours).
Total time over 12 hours for a pair of radius-edged perfect fitting washers.

Brainstorm
Then, a call to the brake mfr: "oh, we have those in stock. I can send you a pair for no cost".

Moral
Always look before crossing. Make that call to the parts maker to see if they have something on the shelf.

Problem
When I was setting up the rear discs on my Dana 60 with late Torino bearings and housing ends, all fit well until I installed the axles with screw-in lugs. All the bolt heads (12-pointer ARPs) hit the park brake mechanism springs.

Solution
I removed the axles, removed all ten Red Loctited lugs (whew!), and one by one I set up the mill to carefully shave down the heads of the offending lugs for clearance, by half the amount of the 12-point heads.
Total time to machine 10 lugs: 3 hours, and a lot of chips on the floor, 2 hours to clean the threads of residual red Loctite (both axle flange threads and lug threads) and re-install and torque the lugs: 2 hours.
Total time: 5 hours, plus a lot of cleanup and setup time on the machine tool.

Brainstorm
Made a call to Strange to ask if anyone else had this problem with interference between the axle lug heads and park brake springs.
"Oh sure, all the time, it's normal. We stock the correct lugs right on the shelf. Didn't we send them to you?"

Moral
Always look before crossing. Make that call to the parts maker to see if they have something on the shelf.

Problem
A while back I needed a complete clutch linkage for the '55 ex-race car I bought after finding it sitting in a closed-down gas station. It had been sitting inside since 1970, and was complete as a D/Gas race car but lacked the clutch linkage to shift the Rock Crusher with Crashbox Dogs.

Solution
I decided to adapt an earlier linkage and from a '52 Bel-Air, and make my own Z-bar. At the time all the repro stuff was seriously junk for a HP car.
After several trips to the steel yard following hours of research into metal alloys capable of withstanding pressures found in a 3,000 pound race clutch, I spend about 25-30 hours fabbing up the entire system and welding and gusseting to prepare for race use. It needed to be as strong as factory, which has always been ok for race use over the years. Basically an entire week of work, scrapping 2 or 3 prototypes along the way as I learned the intricacies of clutch linkage geometry.

Brainstorm
For grins, I thought I'd tease the local Chev dealership parts counter guy and call up and ask if there were any 1955 clutch linkages in stock. 
"Yes, we have one, it has the Z-bar, the rods, and the mounts to the frame and some other stuff. Do you want us to put your name on it and you can come in and pick it up?". "Yes. How much is it?" --checking-- "35 dollars for everything."
This dealership didn't come into being until 13 years after the '55 was made. There was nothing special about the dealership... not like Nickey, or Dana, etc. But they had extremely rare parts, brand new in boxes, for a 30 year old car sitting on the shelf next to the Lumina and Corsica parts.

Moral
Always look before crossing. Make that call to the dealer to see if they have something on the shelf.