The problems with vintage horns seem to be: 1. LH Thumb Rest/Octave Key Spatula - replace the rounded, arm-numbing button with a flat or contoured rest. The Martin Indiana style rest is very comfortable. The spatula is shaped to match the new rest. LH hinge (selmer style) is also possible 2. LH Palm Keys - replace spatulas with modern shaped brass spatulas, form fitted to the player's hand 3. Front F - add a front F spatula key 4. Bb Bis Key - reposition closer to the B key. Optionally replace with special spatula. 5. Hook Ring / Horn Balance - move the hook ring so the horn is balanced 6. RH Thumb Rest - move thumb rest so the thumb is directly under the index finger. On some horns this requires patching the original chromatic F# tone hole and making a new and smaller (Martin Style) hole higher up on the back of the horn. An adjustable thumb hook is an option. 7. Side Bb Key - many side Bb keys are hinged too close to the key cup so the key travel at the spatula end is excessive. Additionally, the lever then has so much leverage, that even the slightest brush with the RH causes the key to open. The action feels weak as there isn't a spring strong enough to offer sufficient resistance. The fulcrum gets moved towards the spatula. 8. General feel of size and comfort - grinding down the finger pearls to where they are just slightly convex, with rounded edges, makes the horn feel much smaller. Small adjustments to the key arms (bending) and angle of the pearl buttons also make a huge improvement. 9. LH Table Keys - By far, one of the biggest issues. Most repair shops are now offering or planing to offer modern key work for vintage saxes. All, that I know of, other than myself, are using prefabricated keys (Yamaha or other brand). Some are cutting the body in half to offset the stacks, and running the rods down the right side. Some are moving the LH bell tone hole to the Right. Some are replacing the entire bell section. I offer a modified LH hinged solution which had been around for just over a year now. it lengthens the LH lever arms, adds new contoured spatulas, and repositions them for optimal comfort and efficiency. The newest version is an adaptation of the Mk6 RH hinged mechanism, which uses the original bell, tone holes, and most of the original mechanism. The Bb AND the B spatuals tilt and are linked to the C#. The C# is articulated on the LH side and works flawlessly. Sliding rollers on the R/L linkage provide adjustment for leverage and key travel. Picts of it in it's unbuffed condition, on a Conn Chu tenor are here. www.martinmods.com/before.jpg www.martinmods.com/33.jpg www.martinmods.com/34.jpg www.martinmods.com/36.jpg Which design is best? Who knows. We'll have to have a LH Mod Shootout to find out. email me a info@martinmods.com for more info.