Your 1915 Erfurt appears to be a Kar98a modified between WWI and WWII by Poland. I have seen some in which they modified the front end of the stock with a Gew98 type front band, but never one that kept the stacking rod with that modification. In any case, your rifle would originally have had a German type stacking rod but now it has a Polish type.
Your VZ24 was accepted by the Czechoslovak Army in 1938 and was probably sold, unissued, to Romania in the first Romanian contract. After WWII Romania scrubbed almost all of the Romanian crests and some of the lion crests. It looks like they got yours. The sling is not correct; I think it is Swedish.
Most, maybe all of the 1918 Orberndorf Gew98 rifles were sent to Turkey where parts often got mixed. I suspect that is where yours came from.
The previous owner did sand the stocks, but not nearly as bad as some were done. I think you got a good deal overall but I don't like to publicly guess at value.
You would get the best evaluation of the Springfield and Enfield by posting the photos in the appropriate forums.