Hi:
Sorry to hear about stolen instruments. I know from experience how it feels. I can also share that one of my guitars found its way back to me. Here's what I've learned:
1. You've taken important steps already in filing a police report and using social media. The online musical community is proactive about helping to find stolen stuff. I bet your odds of being reconnected with your guitars are better than ever.
2. Having the serial number of instruments is super, super important. If someone tries to sell a stolen instrument, a responsible potential buyer (like the guy who owns a music store or pawn shop) will Google the brand, model and serial number. If it comes up stolen, he's likely to report it. (Any vaguely legit business wants to stay on the right side of the law.) Similarly, a musician who buys a used instrument is not unlikely to Google the serial number of his new purchase, which, again, can lead the instrument back to you. (I think that typically, if someone learns that they unknowingly bought a stolen instrument, they'll do the right thing, one way or another...that's pretty much what happened in my case.)
Conversely, a business owner (or musician) can't be expected to comb the internet for every reportedly stolen instrument that matches a particular model and description without a known, posted serial number. Searching the s/n is reasonable due diligence on their part.
I just Googled "Santa Cruz Tony Rice 5320", and the 5th result is about it being a stolen instrument...very good. I also strongly advise posting brand, model, s/n on a "regular" website in addition to social media sites like facebook. You don't want someone to have to sign in or be a member of a site to quickly click on a search result and confirm that their search query is a stolen item. Think in terms of keywords and search results. Clearly post "brand XXX model XXX serial number XXX STOLEN". That's what a responsible potential buyer will look for.
3. Maybe I missed it, but I didn't see a s/n posted for the dobro. If you don't have the s/n, try to think "outside the box" to find it. Whoever you bought the instrument from may have a record of it. Did you ever have work done on it? Many repair shops keep that info, and may be willing to dig thru some paperwork to find it. It's even worth the money if they charge a fee to search. Could it possibly be in a photo (a long shot,I know)...etc? If you absolutely can't come up with the s/n (or even if you can), write down the numbers of all your other instruments right now. Don't let this happen again.
4. While remaining super diligent about tracking down your stuff, take some consolation in knowing that it's just an instrument. You may never get another that you love quite the same, but nobody got physically hurt, and you can at least come reasonably close to finding a replacement. You'll build a new relationship with another instrument and it will be OK. As much as what you're dealing with really sucks, nobody wound up in the hospital.
Sorry for such a long post...I really hope this helps.