It is certainly feasible.  Getting the parts might be more difficult.

I have part of a power steering kit that I pulled out of an 89 360 GLE
car that had to be scrapped due to chassis damage last year (lost the
reg with it too, due to no MOT when it was stolen...FXI 360..bastards).
 I have the rack, pump, tank and mounting bits with all the unions
still together (never taken apart except to replace the rack with a
recon unit, so the rack is new also), but I didn't have time to get the
steering column which is also different to the 87 360 GLE car I have in
the garage.

I think the parts are worth £100, the steering column would be about
£30.  Fitting would take about 4-6 hours I guess if all the parts are
there, say £150 for a reasonable garage.  So guts of £300.

I'm not sure I want to part with the kit and I'm in N.Ireland so
collecting the stuff might be difficult and there are no 360s in local
scrap yards (for the column), never mind ones with PS.  In England you
might a better chance, but again it is only 89 cars that have it.

--
Tony

   Before you try power steering, try a narrow, all-season tread
tire on the front, inflated to near the maximum. I own a 1986 Si
that I bought new, and the car - which also lacks power steering
- is very sensitive to what kind of tire it has on the front. I'm
currently using all-seasons on all four wheels that, while a size
larger than OEM, don't put all the tread in contact with the road
except when cornering. The steering isn't *quite* as good as it
was with performance tires, but it's very light, and fuel economy
is also higher.

Thank you all for your suggestions. I shall enquire about the tyres -
sounds interesting - although just before I tucked the car away in the
garage, I had replaced the tyres. My family couldn't believe I am
actually dealing with this situation at last!  My head tells me to sell
and get a new/newer car but then I think of how many years we have been
together, how wonderful a drive it has..... and then my resolve just
disappears. Oh well... ....