well this is an interesting turn of events. I say that because I am the "someone who thought it would be a good idea to convert it to 45ACP". for the record, that rifle was built from a pile of scrap parts. it is why you have a t receiver with the L style flip peeps, why one of the scope mounts is missing (was busted off back in the days that these sold for $50 and the guy just junked the whole rifle), and it's cobbled together in general. I also toyed with the idea of restoring it to original configuration, but ended up obviously not doing that, and here were my basic thought processes for doing so.
1. at the time, the 45ACp conversion was advertised as a cheaper alternative.
2. there is not a single matching serial number on that gun, mostly because it was built in someones basement from several stacks of parts. what parts couldn't be scrounged were either added by the 45ACP conversion or had to be ordered from numrich, hence no collectors value, and no real reason to restore in the first place.
3. even if you spent the $2000+ to build a T reproduction rifle, it would still have zero matching serial numbers, no collectible value, and you'd still be stuck with a $500 gun that has way more into it than it's worth(only thing keeping the value above $100 is the T on the side)
I got in way over my head and the kit did not perform as advertised and I ended up getting in a giant peeing match with the manufacturer which eventually led to nowhere. without any gunsmithing skills to correct the shortcomings of that kit I traded the whole gun for a single new tire for my truck. the guy I traded to tried a lot of home gunsmithing and sent it away to a professional for a little more, but without any real understanding of the manufacturer's thought processes, I doubt they made the gun any more reliable or functional. I think given basic investment-return associations, your most cost effective thing you could hope for would be to just dump $500 to a local gunsmith and hope he knows enough to get the gun functioning properly. Charlie Driver in Culdesac generally gets good reviews on his work, but I could never figure out how to get a hold of him.
if you intend to restore it, here is a complete list of everything you'll need.
303 brit barrel with front sight post intact.
complete stock set (which with enfields almost always require special fitting)
front and rear barrel bands
new rear peep(which is a pain because of the spring loaded detent.
a new extractor(because of modifications made during the conversion process.
a new ejector(original is missing because of the conversion.
a new rear scope mount.
the scope rail itself, when a reproduction rail can be found usually runs several hundred dollars.
cost of a scope of course.
the Ts require a riser block to be bolted onto the buttstock to raise the cheek weld to a decent level.
magazine
... all of this is assuming the previous owner hadn't made further changes since the last time I talked to him
I hope you get the century back up to snuff. it should prove a little more economical to work with.