Early 30's Harmony Guitar Restoration. Help and info needed!

[Speedy77]

Let me start off saying I really appreciate everything you guys do. This is an awesome community, and I'm glad to be posting here! I'm sorry for any questions you guys might think are dumb, however I want to ask to make sure I make the right decisions on this project. I hope you understand.

I just picked up an early 30's Harmony Supertone Bradley Kincaid Houn' Dog from a local buy and sell for $12.50. It's in pretty rough shape, with a badly cracked bridge that needs replacing, none of the original bridge pins, a bad crack on the front near the sound hole, and split down the back, and a totally missing fretboard. The tuning machines are in good shape (thank goodness!) and the guitar seems pretty structurally sound. I want to make this guitar as true to the original as possible, so I would like to use all original materials. I have plans of recreating the bridge using rosewood like the original, and attempt to buy aftermarket wooden bridge pins and inlay some mother of pearl in them. I've looked all over the internet for the original info on the guitar, however, I'm unsure of a few things.

1.) What would the fretboard have been originally made of?
The fretboard is described as being "ebonized hardwood", however it's unclear what kind of hardwood this was. If anybody has any info on what Harmony (or any other guitar manufacturer) used for ebonized fretboards at the time, that would be great!

2.) What would be the best way to fix the deep gouges and scratches while retaining the value of the guitar?
I'm hoping on fixing the very bad looking scratches and gouges in the body. These are not the "cool" looking scratches that make a guitar look worn, but instead they're deep gouges that make the thing look like it got tossed around an awful lot. I was hoping on fixing these chips/gaps/gouges/scratches with some sort of wood filler that matched the color, but wasn't sure if this was a big no-no or if there was a special way to apply it with the wood's finish in mind. Maybe some on-the-surface thick scratches should be restained? To be honest I'm not really sure, but figured you guys would know!

3.) What's the best way to finish the guitar/fretboard/bridge/bridge pins?
After fixing scratches on the body with filler or stain, should I spray the body with a few coats of nitro to seal everything together and protect the fixed areas? Or will this ruin the sound/quality of the guitar? Also, when I finish the fretboard, bridge pins, and the bridge, what type of finish should I apply that would either be true to the period or something that's much better than what they used to use back in the day? Just looking for some ideas, you guys are much more experienced than I.

I've worked on guitars before, but this is the first one I really want to make true to the original. I understand that nothings going to be perfect, but who's saying it can't be close! Hopefully I'll learn a lot from this project. Thanks for reading, and hopefully we can find some cool ways to get this project done!