Are you looking for a bolt on mechanical thumb or a weld on? There are tons of weld on thumbs. Just google them and you will be overwhelmed. There are also some bolt on's as well but they are more specific to your BH. If money is not an issue I would suggest you get a hydraulic thumb instead of a mechanical. If you are going to use it any amount of time you will find that this will be a time saver. You can use it when you need it and you do not have to get on and off of the BH to engage it for maybe some rock or something and then have to do the same all over again to keep digging.
I have a bro-tek on my 8B. It is a good robust and solid thumb and it is a bolt on so no welding needed. You can find it here Bro-Tek and there is one for your 48 BH. The negatives are that you have to use it with a toplink and the toplink has to be removed totally when you store the thumb. That is a negative. The thumb works good and is really rigid when it is engaged. Lots of pieces and more work to extend it and retract it. At one time the owner/designer was talking about making it hydraulic but that did not come to pass. The owner is a really nice guy and does good work.
If you do a search on me you will find some pics and video of using the thumb.
I have thought seriously about getting a thumb from this company Hound Dog Backhoe Thumbs. They make both a mechanical and a hydraulic thumb. They are weld on so if you do not weld then someone will have to do it for you. They are a Kioti dealer but they make them for all BH. If I remember they will custom fit. I like what they have to offer and truly like the hydraulic aspect of it.
Again do a search you will be amazed with what you will come up with.
I trust that you will find what you need when it comes to a thumb.
I do weld (Have a Miller 252) and am open to either welding or bolt on (being lazy, if the bolt on works just as good, I'd go that way), but I'm a bit hesitant to weld on, only to find the thumb is too flimsy and or the teeth are not long enough....
I also do have an interest in a hydro thumb, but again, I have not seen any that specifically associate with the 48.
As to the links you gave (thank you btw), I was at the Bro-Tec site and just could not get a clear enough pic to see the unit (and again it does not talk about teeth length).
I have also reached out to the ebay sale a couple days ago, and again, no responce.
On your thumb, how long are the teeth and are you happy with the length?
Go to these posts and you can get a good picture of the Bro-Tek thumb. I am assuming that the length will be the same for the 48 since it is so similar to the 8B and I think that the length will be plenty. The teeth on the Bro-Tek are pretty descent and I believe they have worked well. This gives you a good view of the design and how it works. I hope that the pictures and videos will be worth more than a thousand words for you!
1, 8, and 13. Posts 61 and 62 are with the Bro-Tek ripper on instead of the bucket.
P.S. As I stated in my original post, I want to move to somthing else, not because the Bro-Tek doesn't work. It works fine in my estimation and it is very robust. However I want a hydraulic thumb and as a mechanical you have to take always remove or install the top link in order to use the thumb. This can be tedious and time consuming when you have to jump on and jump off the BH but not only that you have mess with the top link. Other mechanical thumb's store their equivalent of the top link right with the thumb and they are easier to work with.