To find the model reference number and movement type and serial number you need to take it to a watchmaker that has tool 107 or the adjustable tool to remove the crystal. With this watch the entry is through the top.
If it's been some time since it's been to a watchmaker it's probably due for a service. A little TLC for it and you'll not only have a nice watch but a great keepsake. While the watchmaker is in there have him make a note with those numbers or better some pictures, too.
As to value if you look on something like eBay and type in Omega Dynamic you'll get an idea what they sell for. To me the value of a family keepsake is a little higher...
I have one of those with that "racing" dial in the shop now. Can't wait to get it back...