Custom Time Signature

[Kevin Patrick Barry]

Dear LilyPond experts,

I would like to display the time signature 4/2 as two struck Cs next to one another (no 'plus' sign), as in the score here: http://petrucci.mus.auth.gr/imglnks/usimg/4/4d/IMSLP39751-PMLP02062-Schubert-Impromptu-Op90No3.pdf

The best I can do with \compoundtime is to get it to show 2/2 + 2/2, (both numeric, with a plus sign).  I looked at a few snippets on the the LSR, but none of them are suitable.  Could anyone please help?

Thanks in advance,

Kevin Barry