Justy Steering wheel shake when braking

I have an awesome Subaru Justy, it is the DL trim from 1988 with a 5speed manual and fwd transmission, I have a bad shake in the steering wheel when i bought the car. I have spent just over 500$ at mieneke in just labor fees trying to resolve the problem. First I had both the FL wheels bearings replaced with a new rotor and they noted that the outer race of the bearing was welded to the knuckle so they wanted to replace the entire knuckle at that time as well, i supplied a knuckle from a parts car i have and they installed the new bearings and rotor on the replacement knuckle. when they gave me the car back they noted i would soon need a head gasket because they found oil in the coolant overflow tank. I got a new HG. and have replaced that myself with no trouble at all. when I replaced the HG. i flushed the coolant and did an oil change. i only had oil in the overflow tank and no smoke out of the tailpipe or no coolant in the engine oil. a week after having the bearings,knuckle,and rotor replaced the original problem was back, not all of a sudden but little by little it came back to full effect(harsh shake only when applying the brakes) I had called the shop and they wanted me to bring the car back in for inspection. I dropped it off and they told me that they did hear a noise from the lf but that the RF wheel bearing was bad so they would have to replace that in order to diag. the noise. I said ok and called them a few hrs later to see how it was going. they said “everything was welded up on this car” the RF outer tie rod would need to replaced because they had to cut it out. I had one that was in great shape on my parts car so i supplied the outer tie rod end for them. so when i picked up the car i headed down down the taconic at about 60 miles an hr. for 100 miles to have the cars windscreen replaced from prior damage. i had the same problem the frirt time i hit the brakes from 50 mph. a hard shake in the steering wheel. turning the car l&r, flooring it from a start, and full lock turns in a parking lot all had normal operation with no problems or imperfections to be noted. i got under the car at a gas station and putting my hand on the RF tie rod jam nut reveled it was completely loose, i had a vice grip so i snugged it and called the shop. they said anything could happen and to drive slow then come back to the shop when i returned. so the next day i came back to the shop and the owner had a tech go with me for a ride. he drove. after the ride the tech said to the owner “yes, you have a noise from the fl,and its definitely the rotor, the rotor is warped” i am out of funds right now so they told me to just replace the rotor myself. it was a new rotor from advanced auto parts so i tool it off and got a replacement rotor, installed it and i still have the same original problem in full strength, no driving noise at all except when you apply the brakes. when you apply the brakes you get a hard shimmy from the steering wheel.