First I like your design concept the way you converted the bottle jack to become your pump by remote mounting an oil tank.
I do see some potential issues you will have to correct eventually though. The mounting of the bender plates will need more support. Your pump has the potential of creating between 6000 to 10,000 PSI pressures, the cylinder depending on what piece of equipment it originated from may be rated at up to 6000 PSI and just looking at the probable internal piston diameter it could have an area large enough to have an output force of up 12 to 16 tons @6000 PSI. This could bend the main channel frame or simply just tear off the welds holding the top and bottom plates on. The good news is if you see this happening all you have to do is to create a top frame like the bottom frame and increase the weld area on both plates
Other than that I really like the build. Not that my opinion matter much.