There are two sizes from TC, 12" LOP (youth) and 14" LOP (full).
I have all factory buttstocks in youth model or Bantam as I am not a big fellow at 5ft 6 inches.
I have made a couple of sets of contender furniture on request and have made them both at 14" LOP.
... just check a few of my creations and they are 14 5/8"
The yardstick method of measure usually determines optimum LOP for an individual.
( A quick & easy non-technical way to determine length of pull is take a yardstick:
Bend the shooting arm @ 90 degrees @ the elbow. Place the yardstick in the crook of the elbow & along the inside of the fore arm.
Bend the trigger finger, as if caressing the trigger, & read the measurement off the yardstick.
That's your LOP)
You can remove the recoil pad on your buttstock and insert a spacer to increase the LOP.
The level of cosmetic consequence relies upon your skillset.
A local gunsmith would be glad to accommodate you.
For a retail source of contender furniture, Marty @
http://www.hausofarms.com/ is the man, for sure!
The rynite stocks from TC are another animal completely.
Super light ... I have a pair and use one that I filled with packets of lead shot for shooting from the bench some of the more stout chamberings.