From the Google My Business [business.google.com] you can edit the listing. I believe from there you need to make sure that the Shared Endorsements are turned on in the Settings. Also make sure the Reviews tab is visible to visitors.

Thanks hard to follow without screenshots, as Google + is so convoluted.

Agreed. Too many products were merged and the back end just seems to have become more complicated, especially for Business accounts.

Actually now that I think about it, I may be confusing my Google + page with Google my business pages which used to be called Local or Places. That said, when it comes to reviews, is there a simple chekbox one can check and uncheck?

The G+ Pages and Location settings are all accessible from that link I gave above as long as you have tied things together by verifying the Google Maps listing. From the Brand Page (or Location), Manage the page, click the icon in the top right corner where your account settings are (you should now be in the Page account). Then go to Settings > Shared Endorsements as I mentioned earlier.

the Google help for reviews is here [support.google.com...]

Link is just a generic link with generic info... so Sadly this post is a waste of time.

As you apparently haven't bothered to go through the steps I outlined, the help link would probably not be of much assistance, I agree.

Thanks Bill, we all least you are helping! But you don't know in reviews are easily shut on or off, or you have to nuke your whole business page if you don't want to participate in the future?

Also, strangely, my Google + page does not rank in Google for my name, any idea on that? I have photos and comments etc, you would think it would be boom, on page 1 yet nowhere.

Turning your Google Page off or disassociating yourself from the Local listing will only stop your participation in the reviews. It won't remove the reviews or turn them off it seems.

So once you dive it it's forever?
Also, again: Also, strangely, my Google + page does not rank in Google for my name, any idea on that? I have photos and comments etc, you would think it would be boom, on page 1 yet nowhere.

You might find insight on this related discussion (from 2014) because someone else had a similar question: [webmasterworld.com...]

Thanks, did not understand or get anything out of that thread. Except the question was similar. I would thank both a google + non business for my name would get page one for google searches NO? and ditto for business... Facebook ,Twitter, Linkeden, Tumblr is on page one, what's up with Google properties?