Fitting big rca plugs into old Scott TUbe amp

I have just received an old tube HH SCOTT 299A amp and realized my rega p3-24 turntable's rca plugs are too big to fit into the rca ins on the Scott. The Scott's rca ins/outs are too close together so basically any rca plug that has a wide diameter enclosure is not going to fit. I tried looking for a way to remove the enclosure and back it off but there's no screw device to take it off.

Any ideas?
I have an hh scott 340b. a couple of years ago I used the phono section with a rega p-5 turntable. the ends of my rega rca casings are threaded and can be unscrewed and then slipped down the cable. by moving the casing on one of the rca's, I was able to connect both rca's into the reciever. if you can't unscrew your rca ends, you could put female to female connectors on the rega rca's and then use rca's that do unscrew. (the phono section on the 340b is mm)
Thanks Muddys. I'll have to scrutinize the rca's again to see if mine is similar to yours. I don't recall there being any threads but i'll double check again. Worse case, i'll do the female connector idea.