Yes you can make a mold of this. I would recommend HS-2 or HS-3 (High Strength series) since you'll need something that can handle some rough handling without tearing and that looks like something that you'll need the flex and stretch of the HS series to demold off of. HS-1 is a bit stiffer and it will flex but with that shape, the 2 and 3 would be better for you.
Also for me, I would glue it down flat like it is pictured and I would also plug up the bottom half of that center hold (I assume it goes all the way through) as it will also help when you demold any castings from the final mold. You would need to drill out the hole in the castings which adds an extra step but I've found that any hole that goes all the way through and is under 1/2" wide is likely to tear or deform after a few castings were made. I am never gentle on my castings when I demold so I've found ways to make my molds last as long as they were meant to even if it means an extra step on the castings. The High Strength series are formulated to withstand a lot of abuse but I've found this extra step also saves on frustration (and time spend on demolding) when they do exactly as they're supposed to and stretch instead of tearing.
Thank you again for answering my question Do I need to do anything to the wood itself? Stabilizer etc?
My wood is pine and the openings/slats in the picture are wider than the ones I'm doing. Mine will be 1/8" and 1/4" (though those do look about 1/4 in picture) I am just too lazy to put mine in my scanner...LOL and there will be 5 and 6 slots. I was going to put the bolt through so the center of the mold would remain hollow.
Lastly, is there a way to take the measurement of the item say in this case it's 4" x 3/4" and input it an online calculator to tell you how much of the product you'll need to one make the mold and two, for future resin castings? I dislike being wasteful. And I to, will probably be a bit rough on the castings.
No stabilizer but you'll need to use a "sealer" of some kind on it - either a spray or a brush on kind. Stabilizer is usually something like cactus juice and that makes more of a mess than anything but if you seal the wood, you will have a lot less problems as wood is porous and moisture will cause the mold material to not cure right. I've used acrylic sealer and a clear resin as sealers and they work well for sealing wood.
Alumilite has online volume calculators on the individual product pages that will do what you want. You can also make the mold box, put the wood in place, and use water or rice to fill up the mold space to get a calculation of how much mold material you will need. For the castings, you can use the rice/water in the mold box and remove the wood piece then add rice/water (measure whichever one you use before you put it in) to fill the level back up to where it was when the wood piece was in the mold box. However much you add will be about how much you need for the castings.
You're welcome and please let us know how things turn out, the more people share their experience the more we know about how the products perform in certain situations and we can recommend them to others.