valve seal/guide confused

I recently picked up a set of ported 340 heads were done by a machine shop.The heads had 2 bent valves. Apon removal of the valves I noticed there was no valve seals on any valves and the valve guides were two different kinds of material (exhaust are brass,intake was steel) at lease that's what they look like. My question is what is the reason for the different guides and shouldn't there be seals. The picture is how it looked after I removed the valve spring. thanks for any info.thumbnail24.jpg