I've recently run into a vintage Ampeg V4B that I'm interested in buying but cant quite narrow down the date. It looks like it's somewhere between 76-79. Are there any obvious tells to give away the year? Have any of you bought a head around this age? What did you pay for it? The link to the head: http://harrisonburg.craigslist.org/msg/4166805026.html Secondly, I run a pretty large rig consisting of both an 810 AND a 215. I've had little to no experience with all tube heads and but love the rich warm tone they push out. I realize that tube power tends to push out more volume to wattage compared to solid state but will this 120ish watt head be able to handle the work load? Any light shed on this would be awesome.