If you can find a backplate for a .20/.25 FP, or TT .25GP, they will work. The trick is finding one. The easy alternative is buying a new CNC'd barstock backplate from Curtis Shipp, a member here on Stunthanger. Look under "Members".  About $12 plus postage. Curtis' address is:  m14m21(at)bellsouth(dot)net

While you're at it, replace the screws with socket heads from the local R/C car store. The head screws are 3mm x .5mm, but the backplate screws are 2.5mm x .6mm. Take samples for lengths, 'cause I don't remember.  I also like to replace the metric hex 1/4-28 prop nut with one that has an SAE hex...a Gr.8 from the local hardware store. Steve

Recently I bought from Tower Hobbies, for an O.S .25 LA, the back plate of TT GP .25 and the socket head screws for it, the socket head screws are made for RC cars. The manufacturer's numbers of those items in Tower Hobbies are:

ASCG2917      Associated Screw Set AE .15 12 (4 of 2.6X12mm; 8 of 2.6X7mm)
ASCC9454      Associated Socket Head Cap Screws M3X12mm (12)
TTRG8023      Thunder Tiger Back Plate GP-25

The original screws from O.S. for use in the back plate are 2.6X8mm, but you can use the 2.6X7mm from Associated, because the aluminum back plate of TT is 1 mm less thick than the original plastic of O.S. The originals O.S. for head are 3X12mm.
Of course, this way you will be paying for and getting a lot more screws (3X more) than you really need.

Luiz  

Optionally, for head, you can buy from Tower:

LXSAU5  Axial Cap Head M3X12mm black oxide (10)
     
Good  Luck.            Luiz

I too just recently purchased a LA 25,, I have a os needle valve assembly and a thunder tiger back plate......Question is Do I need a gasket for the metal back plate?  the os with the plastic does not have a gasket.    which one from thunder tiger would I need

Hi Neil,

Several answers on your other thread.  I use automotive gasket maker (in the tube).  20 years or more now and no problems.

Big Bear

RSM makes a round backplate gasket for the LA25 (no dog ears). They also make delrin verturis for them.