180 lbs dressed - just a guess.

Really, It should be a good buck by the description of your area. But, Even older deer can vary in weight due to the rut, drought, etc. I'd guess its a mature deer definetly worth hunting. I'm sure you have considerable hunting knowledge, so I'll only offer one bit of advice....hunt downwind of the scrape/scrape line - maybe 75 yds in a good funnel area if you can find one. The latest reasearch indicates that Mature bucks rarely work a scrape over once they've established it. The continue to scent check it however, and other, usually lesser bucks, will continue to work it as well.

Good luck, post pics when you take him.