Looks like a Thompson A vise. Seems to me you have to tightern it by spinning the hold down to get to the correct size. I started with one and still have it in the original box. Read the directions with it. It may be a simple adjustment to hold your fly tight.
Well done & as stated . . . welcome to the addiction! And save that one; my Sainted Mother saw my first creation lying on the kitchen table, swatted it & flushed it down the toilet. I don't think she did that because it looked "buggy;" I think the ugly factor came into play.
The good news was they generally looked like a fish might bite it and they were durable. I also picked up an Anvil Atlas for $60. I was able to make the other vise hold the hook well but I had commandeered a shelf as my c-clamp station for this little experiment and my wife wanted it back.
I would`nt fish it . Not because it won`t hook fish - it will . But rather because you only tie your first fly once , and the first is always the one worth keeping .
I wish I had .
Keep up the good work !!