hydraulic fluid reservoir weld broke

Might that mean you can separate reservoir from bracket, tie it up, then pull the Bracket to take it to a shop?

If not, I just might start figuring out a way to strap the assembly in place "some other way."

One of j-d's Proverbs: Necessity is the Mother of... Some Very Homely Children...

If it doesn't leak and only the bracket needs to be welded to the tank that should be easy. Just weld it in place, no need to drain the tank.

If I can figure out a way to unbolt the resivor without having to disconnect all the valves, hose s, wires etc...and get it welded I'll be in business

At the every least you have the pump and the return lines that have to be disconnected from the reservoir

1. How do you identify the return lines and are they under pressure if jack's and slide are not out. In other words what is to be expected fluid wise etc....when I remove them? Also, are there appropriately sized caps to temporarily cap them?

Hydraulic fluid is combustible. Not as bad as fuel, but still.
So any smart welder will not do the job unless you fill it up with water.
Hydraulic fluid is pretty cheap, so I would not worry about recovering old one.
Just drain everything, take the reservoir to weld shop so they can fill it up with water and weld.
Than drain water. blow with air, let it dry on the sun for a day and put all back with new fluid.

Latter...after looking more closely the resivor and the valves, motor etc..arenbopted on to the bracket. So I can remove them by only two bolts. My question now is to see if there is any way to unbolt that conglomerate of valves and limes, set them aside so to speak while the bracket is rewelded to the frame. I'm not sure I would ever find enough markings to mark all the lines. Also, if I do remember any of the returns to empty the hydraulic system...what can I expect...or...I mean I assume just a bucket is needed to catch all the fluid...I'm not worried about save my it...just wondering if any of that system will be under pressure when the jack's and slide are in

Pictures?
System in release mode should not have any pressure. Maybe residual pressure, but all that will show once you crack the fittings.

NO pressure
just residual fluid in the lines

goto to home depot etc
buy some electrical wire marking numbers

mark the lines before removing
take a picture of the marked lines and how everything is placed
take several pictures

review pictures

remove lines and valves