What Strings for Tenor Guitar
 

I am using an old Paramount Guitar, BM 410 N with 4 strings, DGBE, as my four string tenor guitar. It has a scale length of 25" to 25.5", nut to bridge. I want to change the tuning to CGDA. Question is, if I buy a set of Tenor Guitar Strings, will they be long enough? If I buy loose strings, what size should I buy? Will these strings hurt the guitar in any way? It is old but still a good guitar. I know very little about string length and gage. Please advise me. Thank you.

With a 25" - 25.5" scale you've got a plectrum guitar, the tenor guitar's ultra-rare cousin (tenor scale is in the 21" - 23" range). Given that original tuning was CGBD low-to-high (many players used "Chicago" DGBE), under no circumstances attempt to tune it to tenor CGDA regardless of string gauge; if you prefer tuning in fifths, set it up in octave-mando GDAE - no string-tension problems (given the appropriate gauges), and a capo at the fifth fret will give you tenor CGDA...

Thank you. On second thought, maybe a good idea to just stick with what I have until I buy a real tenor guitar sometime in 2018.