Sorry to hear about your dog - sure is tough when they get older and start having old age issues. I sure wish our pets were with us a lot longer.
As to the other stuff - I was wonder if it would be better to replace the whole bottom of the case instead of the broken off edges. Based on what yours looks like, what do you think?
For the wood - plans would be great - and a lot cheaper to ship (or email). the metal parts you'll need to make. But there is no rush on this - I know eventually you'll get to it - it's not like I haven't gotten more than enough to keep me busy for months (or years).