Please help identify Delta shower/tub faucet

[tmcguinn1]

I replaced my mother's bathroom recently, cleaning and replacing the old faucet. It leaks into the knob so I would like to buy parts to fix, but do not know what model it is. It is an 18 year old builder's model. Delta, single knob, lift to turn water on, turn knob to adjust temp, diverter is on spout. At the same time, if it is not too big a deal, I would like to convert it to a lever instead of a knob as my mother has a bad hand. Can anyone help me identify which model and also advise on the knob to lever conversion? Thanks!

 

[Peanut9199]

You probably have this valve if it's 18 years old
http://www.deltafaucet.com/wps/portal/deltacom/kcxml/04_Sj9SPykssy0xPLMnMz0vM0Y_QjzKLN7SMN_YOAckB2ebxYY76kaiCAfFmTkhivh75ualAmUhzoIyhp6U-UJmTfpC-t34AyECYaHhRal5KapF-QW5oRLmhhUeuo6IiAEieXyQ!/delta/base64xml/L0lNN3VhQ1NXWm1abUtDbEVLQ2xFL29Ed1FBRUlRZ2lFQVFoakJLQUFCQUlVb0FBRUFBeWdBQVFBSEtBQUJBRUNvQUFFQWhLZ0FBUUFDcUFBQkFBYU5vMWlBQUJBTk84NzFuQSEhLzRMRTVST2dyZ093NGh1WWRod2pjb2chIS83X1BfMUk5L19zcGFnZXZpZXcvJTB0ZWNoZG9jcy5kbz9wcm9kdWN0LnNrdT02MzYvcHJvZHVjdC5za3UvNjM2#

You can get a lever handle for it

http://www.deltafaucet.com/media/Product_Tech_Docs/Parts_Diagram/Models_601_602_606_611_612_621_5983.pdf