Reddit mentions of Sashco 46090 10.5 oz. Conceal Textured Wood Caulk, Grizzly Brown

The gaps are pretty big, and assuming you don't have very consistent temperature and humidity in the house, they will expand and contract over time. Using wood putty to fill those gaps will work for a while, but will eventually break and fall out. Instead you can use a wood-colored caulk, such as https://smile.amazon.com/Sashco-Conceal-Textured-Caulking-Cartridge/dp/B0082NUIEA/ref=pd_sim_328_2?_encoding=UTF8&psc=1&refRID=RT9KETRB0C5RT6E38H3E

For very large gaps, you can use rope (as they did when building old houses): https://www.youtube.com/watch?v=7focJeab0pM

Your best bet is to insulate from below as well. That will be more effective at keeping your heat/AC inside, though it won't address the visual appearance of those gaps.

Final note: those are beautiful antique floors. Probably original to your house, I would guess they are heart pine from old growth forests. They are probably long boards (10' plus) so this is really an uncommon classic. Take good care of them, and if you ever change your floor, at the very least make sure you sell these to a shop that knows their worth!

Okay so It's a pretty labor-intensive process, so be forewarned

I didn't want to just draw the parts by hand because I wanted the shield to be game accurate, so I took this picture and had it printed on a poster at my local staples, I used the largest poster size, so this was about $20. I then cut out the entire shield from the poster to draw the base, and cut out each of the detail pieces to trace.

I cut and sanded everything with a multi-use dremel. The wood that I used was 1/4 inch birch, which is easy to cut and sand. I got a big sheet at home depot, and I ended up only using half. (I might use the other half to make the Master Sword Scabbard later this year) I would recommend using 3/4 inch wood or layering more pieces than I did, because my shield doesn't have anywhere near as much depth as I would like.

So I cut out the smaller shield pieces for layering by tracing the large shield piece, then taking a 2-3 inch block of wood and running it around the inside edge of the first trace. I made sure the three pieces were centered on top of each other before supergluing them together.

I filled spaces on the layered shield with wood bondo, sanded that down as smooth as possible, then filled all the little holes with wood filler, of course you have to sand this too. Then I painted it with this, but you can use a lighter shade if you want a different look. Finally, I covered the whole thing in newspaper except for the little parts where the border shows through (the silver triangles) and I painted those silver.

For the border I cut the border out of the poster and traced it on the birch, cut it out with a dremel, then cut it into sections and sanded it down. I laid it down on top of shield base (after I had filled it in with the bondo) and filled the gaps between the border parts with bondo. What this does is reconnect the border pieces in a curved manner that perfectly fits on the base. When the bondo dries, add more bondo on the reverse side of the border to strengthen the connection. Then you can sand it down smooth. Spray paint that shit silver and you're good.

For the triforce, pointy decals, and bolts for the border, I cut them out of the poster, traced them onto particle board, cut them out and sanded them to look 3-dimensional. I painted them, and that's that.

Attach all the pieces together using wood caulk. The last step is adding Hylia's Crest, which was frustrating to figure out at first. What I ended up doing was cutting out the details from the poster, tracing them onto this and cutting them out. These decals were a little too pink for me, so I painted them with this glossy red paint. Finally I peeled off the backing and stuck them on the shield.

To hang it up, I pounded some small nails into the back and hung a metal wire between them.

Thanks for your interest. I'd be happy to answer any other questions you have!