I bought this on ebay because it looked unusual and I paid less than $30 for it. Does someone know what it is?

I'm not sure if that extra slide is to tune it to a different key or something from another instrument the seller is including by mistake. In any case I'm curious about the apparently large bore and interested in the challenge of getting the valves unstuck. If I can't make it work I'll stick it on board with some velvet backing and sell it as a decor iterm.

Looks like the kind you make a lamp out of...

I have no clue. What is the deal with the 2nd valve slide? It looks like an extra 1st slide stuck in there. Are there any markings on it at all? I would say that you will need to take it to a shop that specializes in restorations. If the regular 2nd slide is not present, they may need to cut the extra one down to size. Also, the valves may need work etc, etc. It could be an expensive project. I hope you have deep pockets for it.

I'll be surprised if the pistons are in a working condition... and even if it was, I'd be afraid to blow through those pipes...

Originally Posted by Dale Proctor

Looks like the kind you make a lamp out of...

Oh, that's so funny I forgot to laugh.

I think it might be convertible from Bb to A. It looks like the additional tubing in the M shaped slide is the same length as the third valve circuit, so that would lower the pitch 3 half steps.

Good point about the second valve slide. I hadn't thought of that before. I have to figure out what's going on with it when it comes in the mail.

I was kind of interested in the challenge of trying to get the pistons moving. I spent the equivalent of a restaurant meal and a drink on it, so it won't break my heat if I can't get it working. Some things are worth trying, though.

Mitch M was on the right track when he said that it might be convertible. It certainly is, but not from Bb to A, but from Bb to Ab. A Bb to A conversion would be just a very tiny loop - like you find on some 1920's vintage Buescher trumpets that have a rotary valve and an additional loop for A added between #3 valve and the tuning slide.
The fact that this is certainly an Ab conversion should give us a clue about what it was built for: In Germany, Lutheran Church brass ensembles (so-called "Posaunenchöre" or Trombone Choirs) in the tradition of a guy called Friedrich Kuhlo use a different fingering from the usual: Their C is played 1-3. The result is that they can play and accompany choral and organ music without transposing.
Quite a number of these groups emigrated to the USA between 1880 and 1920, sometimes emigrating as a whole group or even parish, and they brought their tradition with them (I don't know if it is still alive somewhere).
Now what happens if a player from one of these groups moves elsewhere and wants to play in a more usual group band or orchestra?
He is STUCK (as happened to me: By mere chance, I started playing in one of these groups, and then joined a British Brass Band... help!!). He has only two choices: Re-learn all his fingering (as I did eventually) or get an Ab instrument (as I did at first...)

As regards the second slide: From the size of it, the slide supplied is the Ab second slide - or maybe (as I did) - someone did not bother and just pulled out #2 slide to the required length.

Oh, that's interesting. Part of my ancestry is German Lutheran so that fits in with my heritage.

I've actually been doing something kind of like that with learning fingerings. When I play music written Bb, what I think of as a "C" scale starts on an open note and ends on an open note an octave higher. When I play music in concert key, the "C" scale starts on the note I call "D" when I play music in Bb.

I look at it as learning two different names for each note and not learning two sets of fingerings, though. It's much easier to just think of an "D" as a "C" and play that way rather than see a "C" on the paper, translate it to a "D" in my head, and play a "D". It saves a processing step.

Originally Posted by Mitch_M

Oh, that's so funny I forgot to laugh....

Glad I could cheer you up...

I think it could be a C/Bb/A, myself, and missing half of its slides.

Tom