Hello Farmersre,
I regret your loss of a brother, you have my sympathies.
By reputation: RHB Sound Dezign
That's a simple answer to your post, but I strongly urge you to reconsider. By all accounts, the Mesa Baron is an excellent amplifier as manufactured. A modifier will swap out parts and alter the amplifier's sound, but only you can determine if it has improved. To maximize your chances for satisfaction, you should become well acquainted with the stock amp so you can communicate what you perceive to be the amplifier's opportunities. You should also realize that modifications of this type will likely result in a decrease in the amplifier's value. Good luck.