A few questions about baritone uke

Hi there! Some might remember me from ages ago, when I first picked up a classical guitar and was struggling through my first few chords. The guitar was our church property and was never intended to stay in one pair of hands for too long, so around Christmas time we had to part and she travelled to a rest home of disabled elderly in a small rural town. Some tears were shed on the parting day, but over all she left happy memories and some very basic skills.

Anyhow, my family was relieved to have some silence at last, but my fingers were itching for playing. However I never really managed to get my head around the 4 fingers/6 strings part and struggled greatly. In my aimmless, instumentless life spent surfing net I became aware of existance of ukes. Found out my cousin owns one. Tried to hold his soprano uke. God, I hated that thing. Yes, comfy for the fretting hand, but the sound was less than appealing to me, and the whole thing just seemed so hideously tiny and toylike. Looking for something similar but more guitar like, I found about baritones. They are hideously rare here, I could not find one to get my hands on. Heck, I could only find one online store that stocked them, and only than only one model. I decided to risk, anyhow they weren't that expensive, like 50$, so I made puppy eyes and said to my dad ''The weather is nice today, you know what I would like for my birthday?''

On 27th of march early in the morning we met. Love from the first sight. Dimavery UK-300 in natural finish, nato body with rosewood bridge and the most carelessly assambled plywood fretboard (chipped than painted over, frets had sharp ends that scratched fingers when playing, fixed that with a metal file) and nylon stings for baritone tuning. Came with extra metal baritone tuning strings, and a nylon set for soprano tuning and actually a bag as well. Over all, less than perfect , but perfect for my needs.

We have had so much fun! She actually sounds more like a guitar than uke, has really low action compared to anything else I have ever tried (I finally can barre, not yet on the first fret, but anywhere else is not a problem), stays in tune for a week solid, she is just the right size to be portable, yet not toylike, I expanded my chord library nearly twice in a month and it's still growing, and I can actually play songs now!

I really wanted to ask for any general advice folks here would be ready to give, as well as where to order strings (the ones she came with sound allright by now, but eventually I will need a change, and I want them to be nylon, but they are never stocked in shops here)

Also, she seems to have changed the timbre dramatically in the last week or so. She used to be rather muted, soft, sort of fuzzy/fluffy. Now she rings totally beutifully, with a bit sharper, more metallic sound (allmost shimmery), it also seems that she has gone a lot louder and requires more gentle strumming. Do instruments mature like that? Or maybe it is just the summer weather and she has balanced the moisture level? (In winter we have terribly dry air indoors)