How old of McIntosh SS stereo anp

Probably worth a shot, but Terry DeWick in Knoxville is more reasonable and is a lifelong Mcintosh repair guru. A variac is needed to power it up though, just powering it up can lead to trouble.

You can't go wrong with Audio Classics.  They recently serviced my C1000 and are able to support whatever they sell.  

I've owned many Mac amps, all of them 20 plus years old. I had a MC-2300 for example and sent it Mac after years of use for a 'tune up', as I figured it would need something.  (Needed the 'mac' crate to ship the beast).  Anyway, between the amp and C-29 preamp that went with it all that was done was a light bulb replacement.  Both units exceeded spec and no repairs or upgrades were needed.  This is very typical of Mac gear, and truthfully of most well made vintage gear.  I thought for sure that they would re-cap something, but there was no reason too.  Mac still services everything they build and their service department is first rate.  
Listen to the amp, if it sounds good and had been cared for buy it.  
Mac served me well for many years.  

Thanks for input. The entry level MC152 is $4500. A bit out of my budget. I'm hoping to find a nice used unit for half that. However, even that is hard to come by 

The 7270 was a great amp. I bought a new one in 1990 ran it for 20 years and it needed nothing when I sold it. Good luck.

leap in !!
Mike Samra from Saginaw is rebuilding my 1961 MC240. Mike is buds with Terry who was busy and Mike does some mods that take amp to next level while modernizing components.
i have a MC250 also that sounds fantastic running brother in Laws Vandersteen2 with ARC SP6 front end
Audio classics rebuilt my MX-110 and did fantastic job !!!

Lots of great feedback with Audio Classics. 

I would think any new McIntosh gear would most likely last the lifetime of the buyer. Key word NEW.
I own a 45 year old MC2105, it's bone stock works perfectly well. Is it up to spec and totally safe to use? No, not likely. The electrolytic caps in this are well past their expiration date along with other items.
I agree with the other reply's great answers.
I had Audio Classics rebuild an MC225 15 years ago very pleased with their team. Order a box from them to ship any Mac gear.
My MC2105 will go to Mike Samra soon for a total rebuild and some modifications too. I've known Mike for many years although we never met consider him a friend. 

I run 2 amps both specced out by Terry DeWick when I got them, an MC250 which was recommended by Terry as very reliable. It was one of Macs 1st ss units and was designed and voiced like their MC275. I tried mine next to a 275 and it was very close. I also have a MA5100 that Terry updated with some new caps when it was showing age. It sounds great and is playing now. I like the old Mac sound so they both fit well. (I do like new Mc but as a retiree that is more than i can swing now.) 
Only caveat on vintage gear is that you want access to a repair source. I live in Hawaii and that is the one challenge....noone here to do it...which is how Terry came into the picture. Dont ask my shipping costs.
If you want to go vintage, Terry is a good source of recommendations as is Audiogon and the McIntosh forum on AudioKarma. Thats how I found mine.