A few cards are missing from my deck. Ca

Yes — a deck with gaps is still readable, with a few caveats.

What's actually affected

• Count first. A complete RWS deck is 78 cards: 22 Major Arcana + 56 minors (4 suits × 14 + 22 trumps). Missing cards change how often each suit and trump shows up, so if a card you need doesn't come out, that's the deck, not the question.
• Reversals flip with the card. A missing card means you have neither orientation of it — you can't get its reversed meaning, because you can't draw it reversed. That's the main practical loss.
• Position-dependent methods get skew. If you count suits or read elemental dignities, a suit short one card will under-report. Plain three-card or single-card readings on position are unaffected.

How to read with it anyway

• Read what's in front of you, position by position, and leave any seat whose card is absent as a named empty seat rather than filling it with a card you don't hold.
• Don't substitute a "close enough" card from memory — that's a card you don't have, and it makes the reading unauditable.
• If the missing cards are few, note them; a spread drawing from a reduced deck is still honest, it just has a shorter deck.

If you'd like, I can do a practice pull on the full 78-card deck so you can compare — say the word and I'll draw one or three.