'72 Swinger Power Steering gearbox rebuild

Mine has sat with the hoses off for 20 years. I had the line openings taped shut but I am just not sure if anything (sand/glass) has gotten inside during the resto process. Also, I cant remember how it drove all those years ago. It had some steering slop but the usual suspension bits were pretty worn out as well. I would hate to get the car all put back together only to have to take the gear back out. Now is the time to go through it.

So, I would like to have the gearbox rebuilt. Does anyone have any recommendations?

Or. maybe there is a simple way to flush it out and test it? I just want a warm and fuzzy before reinstalling it.