The Week 868 Saturday September 14Th 2013

[rtxwdtrier]

I struggled with this one, and the edition with the solution hasn't arrived. Any help please with:
4d "Initially zero mostly on OS railway circulating and West Coast line in red (9)" given as ZINFANDEL where does the West Coast line fit in?
5d "Volunteers in M East republic upset one from nearby country (6) -A-A-I looks like MALAWI, but why?
7d "Not hot, cook reheating dish with a crust (8)" -R-T-N-E is it GRATINEE meaning au gratin?
23d "Lots admitting little space for wooden projections (6)" T-N-N- must be TENONS but why?

[Captain2]

4d Zinfandel is produced in California, hence WesT Coast

[vetuste_ennemi]

Qa(TA)rI[rev]
t(en)ons
re[h]eating [anag]
don't understand wordlplay for Zinfandel

[rtxwdtrier]

Thank you Captain2 and vetuste_ennemi.

[bibblebub]

23d) lots = TONS, little space = EN -> T en ONS

[bibblebub]

7d) yes = anagram of re(h)eating

[bibblebub]

5d) QATARI = T.A. inside IRAQ, and the lot reversed

[bibblebub]

4d) explained here http://www.theanswerbank.co.uk/Quizzes-and-Puzzles/Crosswords/Question1276183.html