Thank you for the question.
I know how you feel here  for my dissertation I sometimes had to read
old articles and the typesetting was definitely offputting. Sometimes
there would be 400page monographs on some geometrical concept with
maybe one diagram, all on a typewriter.
Oddly enough, if you look at some of my math answers on here, (e.g.
clicking "rbnn") you will see that in some ways we have come full
circle  trying to type matrices and nested subscripts into the text
form on google answers doesn't yield very legible results either!
Fortunately, I have found a nicely formatted paper that proves the
Hoffman/Kruskal theorem on integral points of convex polyhedra; in
fact it proves a generalization of it. The paper is:
"Integral Solutions of Linear Complementarity Problems", by William
Cunningham and James Geelen. Mathematics of Operations Research, 23
(1998), 6168.
This paper is in onlinepostscript format here:
http://www.math.uwaterloo.ca/~whcunnin/lcp.ps . It
If you are unable to read postscript on your computer and unable to
get to a copy of Mathematics of Operations Research, you will have to
download a postscript viewer, which is not necessarily trivial.
Instead you may want to try and print out the paper at any postscript
printer. Let me know if you have trouble viewing the postscript,
however, and I can point you to some sites to download viewers from (I
will need to know your platform).
In any case, Theorem 5 is the theorem you want (on page 3).
As always, if you have any questions, please use the "Request
Clarification" button before rating this answer.
Search Strategy

Various permutations on Hoffman, Kruskal, integral, convex, boundary
points yielded various hits, and I read through the links. To get the
citation I examined the URL of the hit on the postscript:
http://www.math.uwaterloo.ca/~whcunnin/lcp.ps , then went to
http://www.math.uwaterloo.ca/~whcunnin to get the list of publications
of the author, which contained citation information for the online
version. 
Clarification of Answer by
rbnnga
on
05 Nov 2002 11:12 PST
Although there are various postscript viewers for PCs out there, I
personally find them a bit hard to install (I use ghostview, which is
excellent, but again, I would not necessarily recommend it if you are
not familiar with PCs too much).
Fortunately, I was able to find a pdf version of the paper here:
http://citeseer.nj.nec.com/cache/papers/cs/10102/http:zSzzSzwww.math.uwaterloo.cazSz~whcunninzSzlcp.pdf/cunningham96integral.pdf
.
Most, or at least some, computers in your department should have PDF
available on them already, so that if you are lucky, you can view the
paper just by going to that URL.
If you are unlucky though, you will have to install a PDF viewer. A
PDF viewer can be found here:
http://www.adobe.com/products/acrobat/readstep2.html . It tends to be
quite easy to install, and it's quite a useful thing to have.
Regarding your question about generality: No, I do not think you will
find that the theorem statement is overly general. (It's not one of
those categorytheoretic statements where you don't quite know what is
being said).
To find this PDF paper, I researched on the title and authors of the
original paper, and "pdf" .
By the way, pdf, especially for TeX converted stuff, sometimes does
not look as good as .ps on the screen; it should print OK though.
