has anyone removed the box & have any tricks or advice?

Welcome to CF! :)
Tricks? :eek:Well.....a gear puller to get the pitman arm off of the steering box shaft. Use some penetrating oil too. Sometimes they need a little help to break 'em loose. Light taps from a brass head hammer will helppersuade it to move.
Hope this helps! ;)

Oh ya,.....take the pitman arm retaining/clamping bolt all the way out.

what is a good place to send the 61 box for reconditioning

Ya might try....
www.ecklers.com (http://www.ecklers.com)
www.mamotorworks,com (http://www.mamotorworks,com)
www.zip-corvette.com (http://www.zip-corvette.com)