Yeah, neither do I.
I didn't even bother to search wether they had more than one model, I just found a couple of photos on Airliners.net...
Edit: Surprise!
Found it!
Photos: Let-Mont TUL-01 Tulak Piper UL Aircraft Pictures | Airliners.net
seems like we were both right!!!
Let-Mont TUL-01 Tulak Piper UL
Remark SP-YET (cn TUL-09)
As far as I can see there is quite a lot of different tails (square, triangular, rounded) on -01s at least on Airliners.net.
Maybe just poor photo tagging and different models or just kit options (I also see tricycles instead of taildraggers)?
Jetphotos lists that same airframe (SP-YET) as a TUL-09 instead:
JetPhotos.Net Photo » SP-YET (CN: TUL-09) Private Let-Mont TUL-09 Tulak by Marcin Glodzik