As to the Spencer's value, that is dependent on which model it is, and condition. Check a copy of "Flayderman's Guide to American Firearms and Their Values" for a nearly current price range, and make sure to read the section in the front defining conditions. This book is usually available in the chain bookstores, and sometimes in libaries.
Also check Flayderman's for value of the Colt.
I don't know if there is a similar value guide on swords. But, of course, you'll first need to find out what model it is and what manufacturer made it.
With that said, as these weapons are attributed to a Civil War soldier, they will be worth more than the values in the guide. If they were *carried* by him in the war (as opposed to being his weapons after the war) they will be worth *considerably* more than the values in the guide. Part of establishing this, in the case of the Colt and the Spencer, will be to find out if the serial numbers are previous to 1866, as they will not be considered CW weapons if they date after early 1865. [As a sidenote, many units were not mustered out until 1866. Some units even continued to enlist soldiers into 1866, and these are considered CW soldiers by the U.S. Government. However, to collectors, weapons dating to late 1865 and 1866 are not considered CW weapons. They are considered "Indian Wars" era. Model 1865 Spencers are not generally considered CW weapons, even though at least some were delivered to units in the field in March 1865. Model 1867 Spencers are definitely not CW weapons.]
I'd be happy to look up the serial numbers of the Spencer and the Colt for you if you post them. I'm not sure if I have the Spencer information, and as I recall, the serial number ranges for these are rather complicated. Others here will have those ranges. I do know that I have the Colt serial number ranges.
IMPORTANT: Do not attempt to clean these weapons, as that will negatively impact the value!