That is also a great looking build, Grant!

With regard to the 50mm bridge conundrum, they are indeed difficult to find in an F-style bridge. I found exactly one:

https://www.stewmac.com/parts-and-ha...AaArolEALw_wcB

Seems like a lot of $$$. So cheapskate that I am, the way I'd be tempted to do it would be to get a set of pressed saddles...

Click image for larger version.  Name: saddles.jpg  Views: 101  Size: 147.5 KB  ID: 45811

...and cut a small notch with a file where I want the spacing to be.

Meanwhile, the lazy part of me would remind the cheapskate that it sounds good and has a nice clean look just as it is and it ain't broke... ;-)