I've had many vintage Marantz receivers and integrateds come through my home. You are wise to zero in on the 2275 or 2270. They're great receivers. I would also throw in the 2245 which is a 2275 with a little less power (basically the same innards, but a whole lot less expensive).
But, understand all but the most thorough of restorations will produce issues for you at some point. It's like buying an antique car, you have to be able to put up with these units going in for repair when problems arise.
Since receivers are trying to do all things, they are more complex (tuner, pre, and amp) and more prone to failure. I would seriously consider starting with a Marantz 7T pre-amp which features point-to-point wiring and is a lot easier to repair if needed, then add the amp of your choice (Dynaco ST-70 comes to mind). You should find some reputable vintage Marantz vendors in the way of Black Swamp Audio, or even some of the members on the the other audio site (AK).
The 7T and ST-70 pair would likely be found for about $1500 which is what I'd expect a fully restored 2275 to cost.
But, understand all but the most thorough of restorations will produce issues for you at some point. It's like buying an antique car, you have to be able to put up with these units going in for repair when problems arise.
Since receivers are trying to do all things, they are more complex (tuner, pre, and amp) and more prone to failure. I would seriously consider starting with a Marantz 7T pre-amp which features point-to-point wiring and is a lot easier to repair if needed, then add the amp of your choice (Dynaco ST-70 comes to mind). You should find some reputable vintage Marantz vendors in the way of Black Swamp Audio, or even some of the members on the the other audio site (AK).
The 7T and ST-70 pair would likely be found for about $1500 which is what I'd expect a fully restored 2275 to cost.