That is, a 135 Full Frame Body!!
Btw, my FA43LE has better Image Quality than my Canon 40mm STM pancake which is yet better than my DA40XS lens on Full Frame (of which the image corner performance is just so poor). So, this adoption is just "unavoidable"! ;-D
Related:-
DIY: Adapting the Pentax FA*85/1.4 onto the Cantax K-5D Mark III
DA40XS Vs EF40STM on 5D3 (Full Frame Shootout Test)