Integrating old kit with OMD-E5

Found some old kit that my dad gave me years ago in my loft and wondered if it was worth integrating somehow into my OMD-E5 system,Theres an old lens which is branded either Topmon or Topman I haven't a clue about the brand at all but it seems in good condition, its a 135mm 2.8 manual focus prime with an adaptor ring. Theres also a Hoya 2 times converter both are Pentax k fit I believe as they fit on an old Chinon camera. Theres also a Chinon flash, I know not to put it directly on the hotshot as it might fry my camera but is there any other way which will be worth me utilising it in some way as ive never used flash before so haven't a clue lol, thanks for any advice

 

Yeah that looks pretty much identical to mine, it seems quite substantial so wouldn't be surprised if it was made by Samyang as mentioned on the link you gave me. definitely seems to be worth a punt anyway as the converters seem to be cheap enough. With the double crop factor that would give me a 270mm, would the 2.8 be a 5.6 then? cheers for the advice on the flash funnily enough I was just reading a little on the Yongnuo flashes last week so will buy one of them as my lighting source, not sure if triggers are cheap or what type are decent, ill check them out on ebay etc... thanks for the advice appreciate it  

 

Thanks Madmaxmedia wasnt too sure