@dhcod
I have looked at your system - and here's my thoughts -
Firstly a friend of mine owned the Leben & Lamm at the same time and I have listened to them extensively. The Lamm, despite being not the greatest in resolution is still better than the Leben - so I can't explain your findings. The Leben misses a lot of detail and he got rid of it.
Now when it comes to MC transformers I have had Garrott modified 103's and still have a 103D long with a slew of other cartridges.
I have a draw full off SUT's - I would not spend $2500 on a SUT because they are a crapshoot - what works for one cartridge can be a disaster on another, even if they have identical internal impedances/specs.
Another example is I have some Altec 4722's and Altec 4629's. The 4629's are as good as any others I have tried including Tim Deparavacini's head and some other super expensive trannies. Now despite the superiority of the 4629 the 4722's which are much cheaper, and less well specced actually sound better with the Denon 103. All my other cartridges the 4629's are clearly better.
The Jensens in the Lamm are mid priced, sound wise they are very neutral - more accurate than most vintage trannies.
One option for you is to either upgrade the Lamm trannies to the top the line Jensen 347 AX series which are much better - you can select the gain that is appropriate for your system and cartridge. Alternatively you could purchase the top of the line Jensens and get them installed in a separate box, which means you could use them with any phono. The Jensen option would cost you significantly less than $2500k and probably be less of a crapshoot.
By the way if you went the Jensen way, the zoebel network can be dialled in precisely to your cartridge by putting it on a scope, with a signal mirroring the internal impedance of your cartridge and adjusting the zoebel network c to create an accurate square wave. This should be able to be done by a competent tech.
Finally if you really want to taste the French Cabernet or Italian Barolo why not try either some vintage Tango or vintage Denon AU1000. At least if it doesn't suit you have a collectors item for resale.
Personally I have ended up with a current based mc phono stage - far superior to any of the trannies and tube head amps I have sitting in the cupboard.
Also I've had the famous Cotters., Quicksilver and they are bleh, as are the Hashimotos, Bob's Devices mentioned above.