Stuck again. Started with this:

*3* *** *4*

**6 *8* 1**

*** 659 ***

*75 *** 49*

*** 9*2 ***

*12 *** 37*

*** 817 ***

**4 *6* 7**

*2* *** *8*

and have managed to get as far as this:

*3* 721 *4*

**6 *8* 1**

*** 659 ***

*75 13* 492

*** 972 ***

912 54* 37*

*** 817 **4

**4 26* 7**

*2* *9* *8*

I have used x-wings in 9s and 6s and candidates in blank squares as follows:

r1c1 =58 r1c3=89 r1c7=5689 r1c9=568

r2c1-257 r2c2=59 r2c4=34 r2c6=34 r2c8=25 r2c9=579

r3c1=12478 r3c2=48 r3c3=178 r3c7=28 r3c8=23 r3c9=378

r4c1=68 r4c6=68

r5c1=348 r5c2=468 r5c3=38 r5c7=58 r5c8=156 r5c9=158

r6c6=68 r6c9=68

r7c1=35 r7c2=56 r7c3=39 r7c7=259 r7c8=2356

r8c1=1358 r8c2=589 r8c6=35 r8c8=135 r8c9=1359

r9c1=13567 r9c3=137 r9c4=34 r9c6=345 r9c7=56 r9c9=1356

I have probably missed something again but would appreciate any advice