Located some NOS 2SK176 if their of interest. Still looking for the 135s - around here somewhere in this DIY raiders of the lost Arc wharehouse
For lateral mosfets I use ALF16n16 and ALF16p16.
You can still buy them from Farnell and RS Components.
I found Newark here (Element 14 there) has the Semelab parts for a reasonable price. However...before I buy all new. I figured seeing as I HAVE J50's here...and extra J49's, if I could find some K135's to swap for, then why buy new? But. if I can't find K135's, then I will just buy all new.