Tough one...
firstly here are Andy pictures scaled down a bit...
Age ?
Since it is a quartz (marked interestingly only on the back) , I'd say sometime from the mid 70's through to mid 80's, probably mid 80's ( it can't be earlier than mid 70's & the mid 80's is a guess ). I guess since quartz was the "in thing" at the start of its life ( & commanded a ridiculous premium ), if the watch was made towards the start of the quartz era ( mid 70's), it would have been proudly marked so on the dial. Since this watch isn't I assume it's somewhat later.
Value ? to be brutally honest, IF it is solid gold, it is probably worth more as a lump of gold, than as an Omega.
If it is gold plated... I have no idea.
Andy, if you have a decent watch maker anywhere close to you, ask him to pop the back off. ( it is not a screw back ), On the inside of the case back, you/he should see a 6 digit number ( or maybe two 6 digit numbers ). this will tell us which model the watch is.
The movement will be marked with a 4 digit number ( the movement type ) & an 8 digit serial number. This 8 digit number will allow us to estimate the age of the watch ( within 2 years +/- )
BTW, you might also want to ask the watchmaker to swap the battery whilst he's in there or at least tell you which battery it uses.
I hope this helps a bit.
Steve