question on harmony strings

[murf]

I am restoring a vintage Harmony H150. It is a student guitar, 3/4 size with ladder bracing, and pinless bridge. I just completed my first ever neck reset, with pretty good result. The dovetail neck had lifted up about 1/2 inch on the back. Using my homemade steamer (football inflating pin + flexible tubing + tea kettle) It came off easily, and I was able to shim , sand, and get a decent reset. I also changed out the bridge (piece of fretwire) for an old leftover compensated bridge I had at home.
Now to my question: steel or nylon strings? I cant find any reliable data on what was original. Pictures on the internet show both. When I got it it had a metal E, and nylon B + G strings. Common sense tells me use nylon with ladder bracing and a pinless bridge, but my first guitar was a student Harmony with metal strings.
I have some FX silk and phosphor martin string at home.011-.047. Can I use these on my little rescue guitar?
Brian