[DeTomaso] gumball pantera shift problems again

[LEVITT1946 at aol.com]

Dear Friends ,
 
After a long year I was able to once again get the car back on the road.  
With the help of a local shop they adjusting my shift linkage and all was 
fine  yesterday.  She passed the nys inspection . 
 
I was a happy camper a few hours ago.Car was shifting but was only able to  
go into reverse when i shut off the car .If I tried to put the car in 
reverse I  could hear and feel the gears grinding .
 
The clutch pedal now feels like it is not engaging at all now. Do you think 
 my master cylinder gave out ? If I try to start the car with it in gear 
but  pushing the clutch to the floor the car jumps.
 
If you look at the clutch and brake pedals they used to be even when  
relaxed.The clutch pedal is now several inches below the brake pedal.Is that a  
sign of something wrong?
 
WTF is wrong now?
 
Regards,
Bob 
 
PS..I have a new clutch master cylinder .Is this an easy  install?