There is a timeshare in Ramona CA called Riviera Oaks managed by DRI I've never heard of a TS called Ramona Oaks
Riviera Oaks is available in 3 ways
a. Own a week there
b. Own pts in Monarch Grand (MGV)
c. Own pts in the US collection by DRI
Not sure how easy it is to find anyone with Riviera Oaks weeks.
BUT there are lots of people willing to give away their MGV pts For a week at Riviera Oaks during peak time you'll need about 144 MGV pts BUT MGV pts are almost always packaged as "points / 24 months". So if you want to go every year you'll need about 288 pts. When I owned MGV pts I saw lots of availablity at Riviera Oaks at all times of the year. IMHO MGV pts would be the way to go if you want to use Riviera Oaks since you should be able to reserve your week ther with little trouble and can also use your pts at any of the other MGV resorts in the SoCal area. The maintenance fees (MF) on 288 MGV pts will be about $1100/year
Owners of resorts that used to be owned by MGV can trade with Interval. You have to open an II account directly with II DRI does not help opening the account.
Hope this helps