Think like getting the bearings out of a saw case?
Might be able to run bolts into those 4, outer/corner holes of the case, to bump on a SOLID surface.
I'm thinking of heating the housing then using ice chunks to chill the brass to get them out.
Get some CO2 - "dry ice" as it would be better than frozen water due to the temperature difference.
IF you try it, be sure to set up the work place first.
Do a dry practice run while wearing your gloves, etc, and see what causes problems with the routine.
Don't want it to bounce like the middle of a work bench will.
If you couldn't -easily- drive a nail into the work surface, then it's too flexy!
Make sure the bolts are screwed in at least -twice- (I'd prefer 3x minimum personally) their diameter so as to not tear out the threads in the holes.
Also make sure the bolts are long enough to allow the bushings room to drop all the way out!
Use a bit of thought on just how hard to bang on things and be sure to land it squarely on ALL of bolt the heads when you do.
Putting them back in may be a bit more involved.
Beating on them (even with a block or socket under the hammer) will likely mush the holes in and then your plungers will gall and hang up in the bores.
Arbor press and some dead true tooling and work surfaces or you'll just cock the bushings and maybe even crack the housing
Plus you get to start all over with the heat & beat process.
Then after you get them in strait, might be prone to leakage around them from whatever looseness any distortion or scraping of the holes that the crooked install caused.
This is just what popped into my mind as I saw the thread and images.
Based on general things that kill many projects.
Hopefully, someone who has rebuilt a pump will come along with some real world knowledge!
Kinda sucks, but sometimes the (proper) tooling costs more than just buying a new unit.
Just have to do your personal math as to if it makes sense to gear up for the repairs or just replace the unit.